21222573400 has 48 divisors (see below), whose sum is σ = 56391413040. Its totient is φ = 7276310400.

The previous prime is 21222573367. The next prime is 21222573413. The reversal of 21222573400 is 437522212.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7578091 + ... + 7580890.

It is an arithmetic number, because the mean of its divisors is an integer number (1174821105).

Almost surely, 2^21222573400 is an apocalyptic number.

21222573400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21222573400 is an abundant number, since it is smaller than the sum of its proper divisors (35168839640).

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

21222573400 is a wasteful number, since it uses less digits than its factorization.

21222573400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15159004 (or 15158995 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 28.

The spelling of 21222573400 in words is "twenty-one billion, two hundred twenty-two million, five hundred seventy-three thousand, four hundred".