216255636 has 48 divisors (see below), whose sum is σ = 563196480. Its totient is φ = 71759520.

The previous prime is 216255631. The next prime is 216255661. The reversal of 216255636 is 636552612.

It is a happy number.

216255636 is a `hidden beast` number, since 2 + 16 + 2 + 5 + 5 + 636 = 666.

216255636 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 216255636.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216255631) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20106 + ... + 28926.

It is an arithmetic number, because the mean of its divisors is an integer number (11733260).

Almost surely, 2^216255636 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 216255636, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (281598240).

216255636 is an abundant number, since it is smaller than the sum of its proper divisors (346940844).

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

216255636 is a wasteful number, since it uses less digits than its factorization.

216255636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9061 (or 9053 counting only the distinct ones).

The product of its digits is 64800, while the sum is 36.

The square root of 216255636 is about 14705.6327983532. The cubic root of 216255636 is about 600.2366066832.

It can be divided in two parts, 21625 and 5636, that added together give a triangular number (27261 = T₂₃₃).

The spelling of 216255636 in words is "two hundred sixteen million, two hundred fifty-five thousand, six hundred thirty-six".