215000640 has 84 divisors (see below), whose sum is σ = 739522524. Its totient is φ = 57332736.

The previous prime is 215000629. The next prime is 215000641. The reversal of 215000640 is 46000512.

It is a happy number.

215000640 is a `hidden beast` number, since 21 + 5 + 0 + 0 + 0 + 640 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 130507776 + 84492864 = 11424^2 + 9192^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (215000641) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 34447 + ... + 40206.

Almost surely, 2^215000640 is an apocalyptic number.

215000640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

215000640 is an abundant number, since it is smaller than the sum of its proper divisors (524521884).

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

215000640 is a wasteful number, since it uses less digits than its factorization.

215000640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74676 (or 74663 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 215000640 is about 14662.9001224178. The cubic root of 215000640 is about 599.0732359176.

The spelling of 215000640 in words is "two hundred fifteen million, six hundred forty", and thus it is an aban number.