23919561 has 24 divisors (see below), whose sum is σ = 36900864. Its totient is φ = 14878080.

The previous prime is 23919559. The next prime is 23919617. The reversal of 23919561 is 16591932.

23919561 is a `hidden beast` number, since 2 + 3 + 91 + 9 + 561 = 666.

It is not a de Polignac number, because 23919561 - 2¹ = 23919559 is a prime.

It is not an unprimeable number, because it can be changed into a prime (23919361) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 18816 + ... + 20046.

It is an arithmetic number, because the mean of its divisors is an integer number (1537536).

Almost surely, 2^23919561 is an apocalyptic number.

It is an amenable number.

23919561 is a deficient number, since it is larger than the sum of its proper divisors (12981303).

23919561 is a wasteful number, since it uses less digits than its factorization.

23919561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1381 (or 1378 counting only the distinct ones).

The product of its digits is 14580, while the sum is 36.

The square root of 23919561 is about 4890.7628239366. The cubic root of 23919561 is about 288.1272947118.

The spelling of 23919561 in words is "twenty-three million, nine hundred nineteen thousand, five hundred sixty-one".