215986988 has 24 divisors (see below), whose sum is σ = 435943200. Its totient is φ = 91715328.

The previous prime is 215986987. The next prime is 215987011. The reversal of 215986988 is 889689512.

It is not an unprimeable number, because it can be changed into a prime (215986987) by changing a digit.

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, 32333 + ... + 38436.

It is an arithmetic number, because the mean of its divisors is an integer number (18164300).

Almost surely, 2^215986988 is an apocalyptic number.

215986988 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

215986988 is an abundant number, since it is smaller than the sum of its proper divisors (219956212).

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

215986988 is a wasteful number, since it uses less digits than its factorization.

215986988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70889 (or 70887 counting only the distinct ones).

The product of its digits is 2488320, while the sum is 56.

The square root of 215986988 is about 14696.4957728024. The cubic root of 215986988 is about 599.9879516099.

The spelling of 215986988 in words is "two hundred fifteen million, nine hundred eighty-six thousand, nine hundred eighty-eight".