21557224507 has 16 divisors (see below), whose sum is σ = 26635234752. Its totient is φ = 16989880320.

The previous prime is 21557224453. The next prime is 21557224517. The reversal of 21557224507 is 70542275512.

It is not a de Polignac number, because 21557224507 - 2¹⁵ = 21557191739 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21557224507.

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 15 ways as a sum of consecutive naturals, for example, 437494 + ... + 484267.

It is an arithmetic number, because the mean of its divisors is an integer number (1664702172).

Almost surely, 2^21557224507 is an apocalyptic number.

21557224507 is a deficient number, since it is larger than the sum of its proper divisors (5078010245).

21557224507 is a wasteful number, since it uses less digits than its factorization.

21557224507 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 922038.

The product of its (nonzero) digits is 196000, while the sum is 40.

The spelling of 21557224507 in words is "twenty-one billion, five hundred fifty-seven million, two hundred twenty-four thousand, five hundred seven".