21057819654400 has 243 divisors, whose sum is σ = 55027232752401. Its totient is φ = 7977162147840.

The previous prime is 21057819654367. The next prime is 21057819654433. The reversal of 21057819654400 is 445691875012.

The square root of 21057819654400 is 4588880.

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

It is an interprime number because it is at equal distance from previous prime (21057819654367) and next prime (21057819654433).

It can be written as a sum of positive squares in only one way, i.e., 7580815075584 + 13477004578816 = 2753328^2 + 3671104^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 6975096091 + ... + 6975099109.

Almost surely, 2^{21057819654400} is an apocalyptic number.

21057819654400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

21057819654400 is the 4588880-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21057819654400

21057819654400 is an abundant number, since it is smaller than the sum of its proper divisors (33969413098001).

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

21057819654400 is an frugal number, since it uses more digits than its factorization.

21057819654400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6102 (or 3045 counting only the distinct ones).

The product of its (nonzero) digits is 2419200, while the sum is 52.

The spelling of 21057819654400 in words is "twenty-one trillion, fifty-seven billion, eight hundred nineteen million, six hundred fifty-four thousand, four hundred".