216405516 has 24 divisors (see below), whose sum is σ = 531522880. Its totient is φ = 68338512.

The previous prime is 216405493. The next prime is 216405517. The reversal of 216405516 is 615504612.

It is not an unprimeable number, because it can be changed into a prime (216405517) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 474346 + ... + 474801.

Almost surely, 2^216405516 is an apocalyptic number.

It is an amenable number.

216405516 is an abundant number, since it is smaller than the sum of its proper divisors (315117364).

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

216405516 is a wasteful number, since it uses less digits than its factorization.

216405516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 949173 (or 949171 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 30.

The square root of 216405516 is about 14710.7279221662. The cubic root of 216405516 is about 600.3752430499.

The spelling of 216405516 in words is "two hundred sixteen million, four hundred five thousand, five hundred sixteen".