215122640 has 40 divisors (see below), whose sum is σ = 516300288. Its totient is φ = 83272320.

The previous prime is 215122639. The next prime is 215122681. The reversal of 215122640 is 46221512.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40892 + ... + 45851.

Almost surely, 2^215122640 is an apocalyptic number.

215122640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

215122640 is an abundant number, since it is smaller than the sum of its proper divisors (301177648).

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

215122640 is a wasteful number, since it uses less digits than its factorization.

215122640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86787 (or 86781 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 215122640 is about 14667.0596917037. The cubic root of 215122640 is about 599.1865272315.

The spelling of 215122640 in words is "two hundred fifteen million, one hundred twenty-two thousand, six hundred forty".