216906536 has 144 divisors (see below), whose sum is σ = 552654900. Its totient is φ = 79242240.

The previous prime is 216906499. The next prime is 216906539. The reversal of 216906536 is 635609612.

216906536 = 3564² + 3565² + ... + 3580².

216906536 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 214036900 + 2869636 = 14630^2 + 1694^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 216906536.

It is not an unprimeable number, because it can be changed into a prime (216906539) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 806210 + ... + 806478.

Almost surely, 2^216906536 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 216906536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (276327450).

216906536 is an abundant number, since it is smaller than the sum of its proper divisors (335748364).

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

216906536 is a wasteful number, since it uses less digits than its factorization.

216906536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 328 (or 306 counting only the distinct ones).

The product of its (nonzero) digits is 58320, while the sum is 38.

The square root of 216906536 is about 14727.7471461184. The cubic root of 216906536 is about 600.8382136364.

The spelling of 216906536 in words is "two hundred sixteen million, nine hundred six thousand, five hundred thirty-six".