13921657 has 8 divisors (see below), whose sum is σ = 15139656. Its totient is φ = 12748032.

The previous prime is 13921651. The next prime is 13921679. The reversal of 13921657 is 75612931.

It can be written as a sum of positive squares in 4 ways, for example, as 6610041 + 7311616 = 2571^2 + 2704^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 13921657 - 2²³ = 5533049 is a prime.

It is not an unprimeable number, because it can be changed into a prime (13921651) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10438 + ... + 11695.

It is an arithmetic number, because the mean of its divisors is an integer number (1892457).

Almost surely, 2^13921657 is an apocalyptic number.

13921657 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

13921657 is a deficient number, since it is larger than the sum of its proper divisors (1217999).

13921657 is a wasteful number, since it uses less digits than its factorization.

13921657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22187.

The product of its digits is 11340, while the sum is 34.

The square root of 13921657 is about 3731.1736759363. The cubic root of 13921657 is about 240.5638190888.

The spelling of 13921657 in words is "thirteen million, nine hundred twenty-one thousand, six hundred fifty-seven".