21557224506 has 8 divisors (see below), whose sum is σ = 43114449024. Its totient is φ = 7185741500.

The previous prime is 21557224453. The next prime is 21557224517. The reversal of 21557224506 is 60542275512.

It is a sphenic number, since it is the product of 3 distinct primes.

21557224506 is an admirable number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1796435370 + ... + 1796435381.

It is an arithmetic number, because the mean of its divisors is an integer number (5389306128).

Almost surely, 2^21557224506 is an apocalyptic number.

21557224506 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21557224506 is a wasteful number, since it uses less digits than its factorization.

21557224506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3592870756.

The product of its (nonzero) digits is 168000, while the sum is 39.

The spelling of 21557224506 in words is "twenty-one billion, five hundred fifty-seven million, two hundred twenty-four thousand, five hundred six".