21391770816000 has 3200 divisors, whose sum is σ = 92210436654336. Its totient is φ = 4887458611200.

The previous prime is 21391770815951. The next prime is 21391770816043. The reversal of 21391770816000 is 61807719312.

21391770816000 is a `hidden beast` number, since 2 + 1 + 39 + 1 + 7 + 7 + 0 + 8 + 1 + 600 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (3200).

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 319 ways as a sum of consecutive naturals, for example, 57350591814 + ... + 57350592186.

Almost surely, 2^{21391770816000} is an apocalyptic number.

21391770816000 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 21391770816000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46105218327168).

21391770816000 is an abundant number, since it is smaller than the sum of its proper divisors (70818665838336).

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

21391770816000 is a wasteful number, since it uses less digits than its factorization.

21391770816000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 491 (or 456 counting only the distinct ones).

The product of its (nonzero) digits is 127008, while the sum is 45.

The spelling of 21391770816000 in words is "twenty-one trillion, three hundred ninety-one billion, seven hundred seventy million, eight hundred sixteen thousand".