21557224497 has 16 divisors (see below), whose sum is σ = 30899496960. Its totient is φ = 13325404752.

The previous prime is 21557224453. The next prime is 21557224517. The reversal of 21557224497 is 79442275512.

It is not a de Polignac number, because 21557224497 - 2⁷ = 21557224369 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21557224427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4020693 + ... + 4026050.

It is an arithmetic number, because the mean of its divisors is an integer number (1931218560).

Almost surely, 2^21557224497 is an apocalyptic number.

It is an amenable number.

21557224497 is a deficient number, since it is larger than the sum of its proper divisors (9342272463).

21557224497 is a wasteful number, since it uses less digits than its factorization.

21557224497 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8046812.

The product of its digits is 1411200, while the sum is 48.

The spelling of 21557224497 in words is "twenty-one billion, five hundred fifty-seven million, two hundred twenty-four thousand, four hundred ninety-seven".