23121657 has 12 divisors (see below), whose sum is σ = 35967204. Its totient is φ = 14228640.

The previous prime is 23121643. The next prime is 23121661. The reversal of 23121657 is 75612132.

It is a happy number.

23121657 is a `hidden beast` number, since 2 + 3 + 1 + 2 + 1 + 657 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 12467961 + 10653696 = 3531^2 + 3264^2 .

It is not a de Polignac number, because 23121657 - 2¹⁵ = 23088889 is a prime.

It is a super-2 number, since 2×23121657² = 1069222044851298, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 23121657.

It is not an unprimeable number, because it can be changed into a prime (23121607) 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, 98694 + ... + 98927.

It is an arithmetic number, because the mean of its divisors is an integer number (2997267).

Almost surely, 2^23121657 is an apocalyptic number.

It is an amenable number.

23121657 is a deficient number, since it is larger than the sum of its proper divisors (12845547).

23121657 is a wasteful number, since it uses less digits than its factorization.

23121657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 197640 (or 197637 counting only the distinct ones).

The product of its digits is 2520, while the sum is 27.

The square root of 23121657 is about 4808.4984142661. The cubic root of 23121657 is about 284.8872314707.

Adding to 23121657 its reverse (75612132), we get a palindrome (98733789).

It can be divided in two parts, 2312 and 1657, that added together give a square (3969 = 63²).

The spelling of 23121657 in words is "twenty-three million, one hundred twenty-one thousand, six hundred fifty-seven".