216403640 has 32 divisors (see below), whose sum is σ = 489073680. Its totient is φ = 86176512.

The previous prime is 216403633. The next prime is 216403697. The reversal of 216403640 is 46304612.

216403640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2837 + ... + 20996.

Almost surely, 2^216403640 is an apocalyptic number.

216403640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

216403640 is an abundant number, since it is smaller than the sum of its proper divisors (272670040).

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

216403640 is a wasteful number, since it uses less digits than its factorization.

216403640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24071 (or 24067 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 26.

The square root of 216403640 is about 14710.6641590378. The cubic root of 216403640 is about 600.3735081786.

The spelling of 216403640 in words is "two hundred sixteen million, four hundred three thousand, six hundred forty".