215620987680 has 864 divisors, whose sum is σ = 889696564848. Its totient is φ = 47377612800.

The previous prime is 215620987667. The next prime is 215620987697. The reversal of 215620987680 is 86789026512.

215620987680 is a `hidden beast` number, since 2 + 1 + 5 + 620 + 9 + 8 + 7 + 6 + 8 + 0 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 50944101264 + 164676886416 = 225708^2 + 405804^2 .

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 211185570 + ... + 211186590.

Almost surely, 2^215620987680 is an apocalyptic number.

215620987680 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 215620987680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (444848282424).

215620987680 is an abundant number, since it is smaller than the sum of its proper divisors (674075577168).

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

215620987680 is a wasteful number, since it uses less digits than its factorization.

215620987680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1170 (or 1152 counting only the distinct ones).

The product of its (nonzero) digits is 2903040, while the sum is 54.

The spelling of 215620987680 in words is "two hundred fifteen billion, six hundred twenty million, nine hundred eighty-seven thousand, six hundred eighty".