216237438 has 44 divisors (see below), whose sum is σ = 486797208. Its totient is φ = 72039780.

The previous prime is 216237409. The next prime is 216237473. The reversal of 216237438 is 834732612.

It is a happy number.

216237438 is a `hidden beast` number, since 21 + 623 + 7 + 4 + 3 + 8 = 666.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 21 ways as a sum of consecutive naturals, for example, 117183 + ... + 119013.

Almost surely, 2^216237438 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 216237438, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (243398604).

216237438 is an abundant number, since it is smaller than the sum of its proper divisors (270559770).

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

216237438 is an frugal number, since it uses more digits than its factorization.

216237438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1863 (or 1836 counting only the distinct ones).

The product of its digits is 48384, while the sum is 36.

The square root of 216237438 is about 14705.0140428359. The cubic root of 216237438 is about 600.2197694925.

The spelling of 216237438 in words is "two hundred sixteen million, two hundred thirty-seven thousand, four hundred thirty-eight".