21120518241 has 27 divisors (see below), whose sum is σ = 30788967027. Its totient is φ = 13951584000.

The previous prime is 21120518213. The next prime is 21120518291. The reversal of 21120518241 is 14281502112.

The square root of 21120518241 is 145329.

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

21120518241 is a `hidden beast` number, since 2 + 1 + 120 + 518 + 24 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 5117256225 + 16003262016 = 71535^2 + 126504^2 .

It is not a de Polignac number, because 21120518241 - 2⁹ = 21120517729 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21120518291) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 84145366 + ... + 84145616.

Almost surely, 2^21120518241 is an apocalyptic number.

21120518241 is the 145329-th square number.

21120518241 is the 72665-th centered octagonal number.

It is an amenable number.

21120518241 is a deficient number, since it is larger than the sum of its proper divisors (9668448786).

21120518241 is an frugal number, since it uses more digits than its factorization.

21120518241 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 894 (or 447 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 27.

The spelling of 21120518241 in words is "twenty-one billion, one hundred twenty million, five hundred eighteen thousand, two hundred forty-one".