216138432 has 42 divisors (see below), whose sum is σ = 572405764. Its totient is φ = 71978240.

The previous prime is 216138431. The next prime is 216138437. The reversal of 216138432 is 234831612.

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 216138432.

It is not an unprimeable number, because it can be changed into a prime (216138431) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 203182 + ... + 204242.

Almost surely, 2^216138432 is an apocalyptic number.

It is an amenable number.

216138432 is an abundant number, since it is smaller than the sum of its proper divisors (356267332).

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

216138432 is an frugal number, since it uses more digits than its factorization.

216138432 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2137 (or 1066 counting only the distinct ones).

The product of its digits is 6912, while the sum is 30.

The square root of 216138432 is about 14701.6472546446. The cubic root of 216138432 is about 600.1281504050.

Multiplying 216138432 by its product of digits (6912), we get a square (1493948841984 = 1222272²).

The spelling of 216138432 in words is "two hundred sixteen million, one hundred thirty-eight thousand, four hundred thirty-two".