216231636 has 48 divisors (see below), whose sum is σ = 541779840. Its totient is φ = 66877440.

The previous prime is 216231623. The next prime is 216231661. The reversal of 216231636 is 636132612.

It is a super-2 number, since 2×216231636² = 93512240814472992, which contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7020 + ... + 21948.

It is an arithmetic number, because the mean of its divisors is an integer number (11287080).

Almost surely, 2^216231636 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 216231636, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (270889920).

216231636 is an abundant number, since it is smaller than the sum of its proper divisors (325548204).

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

216231636 is a wasteful number, since it uses less digits than its factorization.

216231636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15024 (or 15022 counting only the distinct ones).

The product of its digits is 7776, while the sum is 30.

The square root of 216231636 is about 14704.8167618641. The cubic root of 216231636 is about 600.2144011556.

The spelling of 216231636 in words is "two hundred sixteen million, two hundred thirty-one thousand, six hundred thirty-six".