21557224513 has 24 divisors (see below), whose sum is σ = 24612499296. Its totient is φ = 18723619200.

The previous prime is 21557224453. The next prime is 21557224517. The reversal of 21557224513 is 31542275512.

It is not a de Polignac number, because 21557224513 - 2³³ = 12967289921 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21557224517) 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, 6905593 + ... + 6908713.

It is an arithmetic number, because the mean of its divisors is an integer number (1025520804).

Almost surely, 2^21557224513 is an apocalyptic number.

21557224513 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21557224513 is a deficient number, since it is larger than the sum of its proper divisors (3055274783).

21557224513 is a wasteful number, since it uses less digits than its factorization.

21557224513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4365 (or 4342 counting only the distinct ones).

The product of its digits is 84000, while the sum is 37.

The spelling of 21557224513 in words is "twenty-one billion, five hundred fifty-seven million, two hundred twenty-four thousand, five hundred thirteen".