18596561 has 4 divisors (see below), whose sum is σ = 18605412. Its totient is φ = 18587712.

The previous prime is 18596551. The next prime is 18596563. The reversal of 18596561 is 16569581.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 16569581 = 7 ⋅2367083.

It can be written as a sum of positive squares in 2 ways, for example, as 3534400 + 15062161 = 1880^2 + 3881^2 .

It is a cyclic number.

It is not a de Polignac number, because 18596561 - 2¹⁸ = 18334417 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18596563) 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, 725 + ... + 6141.

It is an arithmetic number, because the mean of its divisors is an integer number (4651353).

Almost surely, 2^18596561 is an apocalyptic number.

It is an amenable number.

18596561 is a deficient number, since it is larger than the sum of its proper divisors (8851).

18596561 is an equidigital number, since it uses as much as digits as its factorization.

18596561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8850.

The product of its digits is 64800, while the sum is 41.

The square root of 18596561 is about 4312.3730126231. The cubic root of 18596561 is about 264.9379752786.

The spelling of 18596561 in words is "eighteen million, five hundred ninety-six thousand, five hundred sixty-one".