23553661 has 4 divisors (see below), whose sum is σ = 23621500. Its totient is φ = 23485824.

The previous prime is 23553643. The next prime is 23553671. The reversal of 23553661 is 16635532.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6661561 + 16892100 = 2581^2 + 4110^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-23553661 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23553671) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33396 + ... + 34093.

It is an arithmetic number, because the mean of its divisors is an integer number (5905375).

Almost surely, 2^23553661 is an apocalyptic number.

It is an amenable number.

23553661 is a deficient number, since it is larger than the sum of its proper divisors (67839).

23553661 is an equidigital number, since it uses as much as digits as its factorization.

23553661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67838.

The product of its digits is 16200, while the sum is 31.

The square root of 23553661 is about 4853.2114110144. The cubic root of 23553661 is about 286.6505680221.

The spelling of 23553661 in words is "twenty-three million, five hundred fifty-three thousand, six hundred sixty-one".