215778240 has 84 divisors (see below), whose sum is σ = 742197144. Its totient is φ = 57540096.

The previous prime is 215778217. The next prime is 215778293. The reversal of 215778240 is 42877512.

215778240 is a `hidden beast` number, since 2 + 1 + 577 + 82 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 215778195 and 215778204.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 34582 + ... + 40341.

Almost surely, 2^215778240 is an apocalyptic number.

215778240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

215778240 is an abundant number, since it is smaller than the sum of its proper divisors (526418904).

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

215778240 is a wasteful number, since it uses less digits than its factorization.

215778240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74946 (or 74933 counting only the distinct ones).

The product of its (nonzero) digits is 31360, while the sum is 36.

The square root of 215778240 is about 14689.3920908933. The cubic root of 215778240 is about 599.7945963569.

The spelling of 215778240 in words is "two hundred fifteen million, seven hundred seventy-eight thousand, two hundred forty".