18012592521 has 135 divisors (see below), whose sum is σ = 33769743917. Its totient is φ = 9244453680.

The previous prime is 18012592513. The next prime is 18012592627. The reversal of 18012592521 is 12529521081.

The square root of 18012592521 is 134211.

It is a perfect power (a square), and thus also a powerful number.

18012592521 is a `hidden beast` number, since 1 + 8 + 0 + 12 + 592 + 52 + 1 = 666.

It is not a de Polignac number, because 18012592521 - 2³ = 18012592513 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18012592511) by changing a digit.

It is a polite number, since it can be written in 134 ways as a sum of consecutive naturals, for example, 217019146 + ... + 217019228.

Almost surely, 2^18012592521 is an apocalyptic number.

18012592521 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

18012592521 is the 134211-st square number.

18012592521 is the 67106-th centered octagonal number.

It is an amenable number.

18012592521 is a deficient number, since it is larger than the sum of its proper divisors (15757151396).

18012592521 is an frugal number, since it uses more digits than its factorization.

18012592521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 222 (or 104 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 36.

Multiplying 18012592521 by its sum of digits (36), we get a square (648453330756 = 805266²).

Multiplying 18012592521 by its product of nonzero digits (14400), we get a square (259381332302400 = 16105320²).

The spelling of 18012592521 in words is "eighteen billion, twelve million, five hundred ninety-two thousand, five hundred twenty-one".