215807426688 has 128 divisors (see below), whose sum is σ = 655469136000. Its totient is φ = 61627318272.

The previous prime is 215807426663. The next prime is 215807426689. The reversal of 215807426688 is 886624708512.

It is a tau number, because it is divible by the number of its divisors (128).

It is a hoax number, since the sum of its digits (57) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (215807426689) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5434168 + ... + 5473736.

It is an arithmetic number, because the mean of its divisors is an integer number (5120852625).

Almost surely, 2^215807426688 is an apocalyptic number.

215807426688 is a gapful number since it is divisible by the number (28) 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 215807426688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (327734568000).

215807426688 is an abundant number, since it is smaller than the sum of its proper divisors (439661709312).

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

215807426688 is a wasteful number, since it uses less digits than its factorization.

215807426688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41622 (or 41610 counting only the distinct ones).

The product of its (nonzero) digits is 10321920, while the sum is 57.

The spelling of 215807426688 in words is "two hundred fifteen billion, eight hundred seven million, four hundred twenty-six thousand, six hundred eighty-eight".