13981440 has 144 divisors (see below), whose sum is σ = 48859776. Its totient is φ = 3379200.

The previous prime is 13981427. The next prime is 13981441. The reversal of 13981440 is 4418931.

13981440 = T₁₀₉ + T₁₁₀ + ... + T₄₃₉.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 13981398 and 13981407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13981441) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 42075 + ... + 42405.

It is an arithmetic number, because the mean of its divisors is an integer number (339304).

Almost surely, 2^13981440 is an apocalyptic number.

13981440 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 13981440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24429888).

13981440 is an abundant number, since it is smaller than the sum of its proper divisors (34878336).

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

13981440 is a wasteful number, since it uses less digits than its factorization.

13981440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 366 (or 352 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 13981440 is about 3739.1763798997. The cubic root of 13981440 is about 240.9076739833.

The spelling of 13981440 in words is "thirteen million, nine hundred eighty-one thousand, four hundred forty".