216508404 has 48 divisors (see below), whose sum is σ = 579547136. Its totient is φ = 61624800.

The previous prime is 216508381. The next prime is 216508417. The reversal of 216508404 is 404805612.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18009 + ... + 27519.

Almost surely, 2^216508404 is an apocalyptic number.

It is an amenable number.

216508404 is an abundant number, since it is smaller than the sum of its proper divisors (363038732).

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

216508404 is a wasteful number, since it uses less digits than its factorization.

216508404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9796 (or 9794 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 30.

The square root of 216508404 is about 14714.2245463361. The cubic root of 216508404 is about 600.4703755928.

The spelling of 216508404 in words is "two hundred sixteen million, five hundred eight thousand, four hundred four".