215566228736 has 72 divisors (see below), whose sum is σ = 441454710984. Its totient is φ = 104994570240.

The previous prime is 215566228727. The next prime is 215566228751. The reversal of 215566228736 is 637822665512.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 25344640000 + 190221588736 = 159200^2 + 436144^2 .

It is a super-2 number, since 2×215566228736² (a number of 23 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (53) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7048550 + ... + 7079066.

Almost surely, 2^215566228736 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 215566228736, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (220727355492).

215566228736 is an abundant number, since it is smaller than the sum of its proper divisors (225888482248).

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

215566228736 is an equidigital number, since it uses as much as digits as its factorization.

215566228736 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31247 (or 31233 counting only the distinct ones).

The product of its digits is 7257600, while the sum is 53.

The spelling of 215566228736 in words is "two hundred fifteen billion, five hundred sixty-six million, two hundred twenty-eight thousand, seven hundred thirty-six".