13921997 has 12 divisors (see below), whose sum is σ = 15030720. Its totient is φ = 12889536.

The previous prime is 13921979. The next prime is 13922017. The reversal of 13921997 is 79912931.

It is not a de Polignac number, because 13921997 - 2²² = 9727693 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13921907) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19004 + ... + 19722.

It is an arithmetic number, because the mean of its divisors is an integer number (1252560).

Almost surely, 2^13921997 is an apocalyptic number.

13921997 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

13921997 is a deficient number, since it is larger than the sum of its proper divisors (1108723).

13921997 is an equidigital number, since it uses as much as digits as its factorization.

13921997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 820 (or 803 counting only the distinct ones).

The product of its digits is 30618, while the sum is 41.

The square root of 13921997 is about 3731.2192377291. The cubic root of 13921997 is about 240.5657774532.

The spelling of 13921997 in words is "thirteen million, nine hundred twenty-one thousand, nine hundred ninety-seven".