215515640 has 16 divisors (see below), whose sum is σ = 484910280. Its totient is φ = 86206240.

The previous prime is 215515631. The next prime is 215515661. The reversal of 215515640 is 46515512.

It is a happy number.

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 in 3 ways as a sum of consecutive naturals, for example, 2693906 + ... + 2693985.

Almost surely, 2^215515640 is an apocalyptic number.

215515640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

215515640 is an abundant number, since it is smaller than the sum of its proper divisors (269394640).

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

215515640 is a wasteful number, since it uses less digits than its factorization.

215515640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5387902 (or 5387898 counting only the distinct ones).

The product of its (nonzero) digits is 6000, while the sum is 29.

The square root of 215515640 is about 14680.4509467523. The cubic root of 215515640 is about 599.5511828742.

The spelling of 215515640 in words is "two hundred fifteen million, five hundred fifteen thousand, six hundred forty".