21226681872 has 120 divisors (see below), whose sum is σ = 65693810208. Its totient is φ = 6344179200.

The previous prime is 21226681841. The next prime is 21226681897. The reversal of 21226681872 is 27818662212.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 23847 + ... + 207417.

Almost surely, 2^21226681872 is an apocalyptic number.

21226681872 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21226681872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32846905104).

21226681872 is an abundant number, since it is smaller than the sum of its proper divisors (44467128336).

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

21226681872 is a wasteful number, since it uses less digits than its factorization.

21226681872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 183669 (or 183660 counting only the distinct ones).

The product of its digits is 258048, while the sum is 45.

The spelling of 21226681872 in words is "twenty-one billion, two hundred twenty-six million, six hundred eighty-one thousand, eight hundred seventy-two".