216402988 has 12 divisors (see below), whose sum is σ = 391764240. Its totient is φ = 104470352.

The previous prime is 216402983. The next prime is 216402997. The reversal of 216402988 is 889204612.

It is a self number, because there is not a number n which added to its sum of digits gives 216402988.

It is not an unprimeable number, because it can be changed into a prime (216402983) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 932656 + ... + 932887.

It is an arithmetic number, because the mean of its divisors is an integer number (32647020).

Almost surely, 2^216402988 is an apocalyptic number.

It is an amenable number.

216402988 is a deficient number, since it is larger than the sum of its proper divisors (175361252).

216402988 is a wasteful number, since it uses less digits than its factorization.

216402988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1865576 (or 1865574 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 40.

The square root of 216402988 is about 14710.6419982270. The cubic root of 216402988 is about 600.3729052252.

The spelling of 216402988 in words is "two hundred sixteen million, four hundred two thousand, nine hundred eighty-eight".