21279215443600 has 45 divisors (see below), whose sum is σ = 51123536755977. Its totient is φ = 8511649273920.

The previous prime is 21279215443573. The next prime is 21279215443609. The reversal of 21279215443600 is 634451297212.

The square root of 21279215443600 is 4612940.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 7660517559696 + 13618697883904 = 2767764^2 + 3690352^2 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21279215443609) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 92143477 + ... + 92374123.

Almost surely, 2^{21279215443600} is an apocalyptic number.

21279215443600 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

21279215443600 is the 4612940-th square number.

It is an amenable number.

21279215443600 is an abundant number, since it is smaller than the sum of its proper divisors (29844321312377).

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

21279215443600 is an frugal number, since it uses more digits than its factorization.

21279215443600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 461312 (or 230654 counting only the distinct ones).

The product of its (nonzero) digits is 725760, while the sum is 46.

The spelling of 21279215443600 in words is "twenty-one trillion, two hundred seventy-nine billion, two hundred fifteen million, four hundred forty-three thousand, six hundred".