13991640 has 64 divisors (see below), whose sum is σ = 45208800. Its totient is φ = 3443712.

The previous prime is 13991639. The next prime is 13991651. The reversal of 13991640 is 4619931.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2925 + ... + 6044.

Almost surely, 2^13991640 is an apocalyptic number.

13991640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

13991640 is an abundant number, since it is smaller than the sum of its proper divisors (31217160).

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

13991640 is a wasteful number, since it uses less digits than its factorization.

13991640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8996 (or 8992 counting only the distinct ones).

The product of its (nonzero) digits is 5832, while the sum is 33.

The square root of 13991640 is about 3740.5400679581. The cubic root of 13991640 is about 240.9662435575.

The spelling of 13991640 in words is "thirteen million, nine hundred ninety-one thousand, six hundred forty".