215493990 has 32 divisors (see below), whose sum is σ = 520187616. Its totient is φ = 57131520.

The previous prime is 215493973. The next prime is 215493997. The reversal of 215493990 is 99394512.

215493990 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×215493990² = 92875319452240200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215493997) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15571 + ... + 25950.

It is an arithmetic number, because the mean of its divisors is an integer number (16255863).

Almost surely, 2^215493990 is an apocalyptic number.

215493990 is an abundant number, since it is smaller than the sum of its proper divisors (304693626).

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

215493990 is a wasteful number, since it uses less digits than its factorization.

215493990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41704.

The product of its (nonzero) digits is 87480, while the sum is 42.

The square root of 215493990 is about 14679.7135530636. The cubic root of 215493990 is about 599.5311058815.

The spelling of 215493990 in words is "two hundred fifteen million, four hundred ninety-three thousand, nine hundred ninety".