215804640055664 has 80 divisors (see below), whose sum is σ = 462500294857440. Its totient is φ = 96724301230080.

The previous prime is 215804640055651. The next prime is 215804640055727. The reversal of 215804640055664 is 466550046408512.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 47645492 + ... + 51977900.

It is an arithmetic number, because the mean of its divisors is an integer number (5781253685718).

Almost surely, 2^{215804640055664} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 215804640055664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (231250147428720).

215804640055664 is an abundant number, since it is smaller than the sum of its proper divisors (246695654801776).

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

215804640055664 is a wasteful number, since it uses less digits than its factorization.

215804640055664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4336378 (or 4336372 counting only the distinct ones).

The product of its (nonzero) digits is 27648000, while the sum is 56.

The spelling of 215804640055664 in words is "two hundred fifteen trillion, eight hundred four billion, six hundred forty million, fifty-five thousand, six hundred sixty-four".