13991240 has 32 divisors (see below), whose sum is σ = 31779000. Its totient is φ = 5543424.

The previous prime is 13991233. The next prime is 13991251. The reversal of 13991240 is 4219931.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 12517444 + 1473796 = 3538^2 + 1214^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2756 + ... + 5964.

Almost surely, 2^13991240 is an apocalyptic number.

13991240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

13991240 is an abundant number, since it is smaller than the sum of its proper divisors (17787760).

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

13991240 is a wasteful number, since it uses less digits than its factorization.

13991240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3329 (or 3325 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 29.

The square root of 13991240 is about 3740.4865993611. The cubic root of 13991240 is about 240.9639472478.

The spelling of 13991240 in words is "thirteen million, nine hundred ninety-one thousand, two hundred forty".