13991540 has 24 divisors (see below), whose sum is σ = 30331392. Its totient is φ = 5415840.

The previous prime is 13991533. The next prime is 13991557. The reversal of 13991540 is 4519931.

It is a junction number, because it is equal to n+sod(n) for n = 13991497 and 13991506.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10664 + ... + 11903.

It is an arithmetic number, because the mean of its divisors is an integer number (1263808).

Almost surely, 2^13991540 is an apocalyptic number.

13991540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

13991540 is an abundant number, since it is smaller than the sum of its proper divisors (16339852).

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

13991540 is a wasteful number, since it uses less digits than its factorization.

13991540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22607 (or 22605 counting only the distinct ones).

The product of its (nonzero) digits is 4860, while the sum is 32.

The square root of 13991540 is about 3740.5267008805. The cubic root of 13991540 is about 240.9656694841.

The spelling of 13991540 in words is "thirteen million, nine hundred ninety-one thousand, five hundred forty".