23612561 has 12 divisors (see below), whose sum is σ = 27725940. Its totient is φ = 20049120.

The previous prime is 23612531. The next prime is 23612591. The reversal of 23612561 is 16521632.

It is an interprime number because it is at equal distance from previous prime (23612531) and next prime (23612591).

It can be written as a sum of positive squares in 2 ways, for example, as 18113536 + 5499025 = 4256^2 + 2345^2 .

It is a de Polignac number, because none of the positive numbers 2^k-23612561 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 23612561.

It is not an unprimeable number, because it can be changed into a prime (23612521) 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, 3131 + ... + 7551.

It is an arithmetic number, because the mean of its divisors is an integer number (2310495).

Almost surely, 2^23612561 is an apocalyptic number.

It is an amenable number.

23612561 is a deficient number, since it is larger than the sum of its proper divisors (4113379).

23612561 is a wasteful number, since it uses less digits than its factorization.

23612561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4544 (or 4537 counting only the distinct ones).

The product of its digits is 2160, while the sum is 26.

The square root of 23612561 is about 4859.2757690833. The cubic root of 23612561 is about 286.8893088902.

The spelling of 23612561 in words is "twenty-three million, six hundred twelve thousand, five hundred sixty-one".