215239988 has 6 divisors (see below), whose sum is σ = 376669986. Its totient is φ = 107619992.

The previous prime is 215239963. The next prime is 215239991. The reversal of 215239988 is 889932512.

It can be written as a sum of positive squares in only one way, i.e., 212343184 + 2896804 = 14572^2 + 1702^2 .

It is a congruent number.

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 as a sum of consecutive naturals, namely, 26904995 + ... + 26905002.

It is an arithmetic number, because the mean of its divisors is an integer number (62778331).

Almost surely, 2^215239988 is an apocalyptic number.

It is an amenable number.

215239988 is a deficient number, since it is larger than the sum of its proper divisors (161429998).

215239988 is a wasteful number, since it uses less digits than its factorization.

215239988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53810001 (or 53809999 counting only the distinct ones).

The product of its digits is 311040, while the sum is 47.

The square root of 215239988 is about 14671.0595391062. The cubic root of 215239988 is about 599.2954582104.

The spelling of 215239988 in words is "two hundred fifteen million, two hundred thirty-nine thousand, nine hundred eighty-eight".