13689040 has 40 divisors (see below), whose sum is σ = 32085000. Its totient is φ = 5431296.

The previous prime is 13689037. The next prime is 13689043. The reversal of 13689040 is 4098631.

It is an interprime number because it is at equal distance from previous prime (13689037) and next prime (13689043).

It can be written as a sum of positive squares in 4 ways, for example, as 1354896 + 12334144 = 1164^2 + 3512^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×13689040² = 374779632243200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 13688993 and 13689011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13689043) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10336 + ... + 11584.

It is an arithmetic number, because the mean of its divisors is an integer number (802125).

Almost surely, 2^13689040 is an apocalyptic number.

13689040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 13689040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16042500).

13689040 is an abundant number, since it is smaller than the sum of its proper divisors (18395960).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

13689040 is a wasteful number, since it uses less digits than its factorization.

13689040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1399 (or 1393 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 31.

The square root of 13689040 is about 3699.8702679959. The cubic root of 13689040 is about 239.2164259813.

It can be divided in two parts, 136890 and 40, that multiplied together give a square (5475600 = 2340²).

The spelling of 13689040 in words is "thirteen million, six hundred eighty-nine thousand, forty".