21157086412800 has 540 divisors, whose sum is σ = 81617031852720. Its totient is φ = 5207886397440.

The previous prime is 21157086412783. The next prime is 21157086412829. The reversal of 21157086412800 is 821468075112.

21157086412800 is a `hidden beast` number, since 2 + 1 + 1 + 570 + 8 + 64 + 12 + 8 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 47702461 + ... + 48143939.

Almost surely, 2^{21157086412800} is an apocalyptic number.

21157086412800 is a gapful number since it is divisible by the number (20) 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 21157086412800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40808515926360).

21157086412800 is an abundant number, since it is smaller than the sum of its proper divisors (60459945439920).

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

21157086412800 is a wasteful number, since it uses less digits than its factorization.

21157086412800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 441536 (or 441502 counting only the distinct ones).

The product of its (nonzero) digits is 215040, while the sum is 45.

The spelling of 21157086412800 in words is "twenty-one trillion, one hundred fifty-seven billion, eighty-six million, four hundred twelve thousand, eight hundred".