21872512858 has 16 divisors (see below), whose sum is σ = 38293519104. Its totient is φ = 9174488400.

The previous prime is 21872512847. The next prime is 21872512859. The reversal of 21872512858 is 85821527812.

It is not an unprimeable number, because it can be changed into a prime (21872512859) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16619793 + ... + 16621108.

It is an arithmetic number, because the mean of its divisors is an integer number (2393344944).

Almost surely, 2^21872512858 is an apocalyptic number.

21872512858 is a deficient number, since it is larger than the sum of its proper divisors (16421006246).

21872512858 is a wasteful number, since it uses less digits than its factorization.

21872512858 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33240957.

The product of its digits is 716800, while the sum is 49.

The spelling of 21872512858 in words is "twenty-one billion, eight hundred seventy-two million, five hundred twelve thousand, eight hundred fifty-eight".