216521352 has 24 divisors (see below), whose sum is σ = 586412190. Its totient is φ = 72173760.

The previous prime is 216521323. The next prime is 216521381. The reversal of 216521352 is 253125612.

It is a happy number.

216521352 is a `hidden beast` number, since 2 + 1 + 652 + 1 + 3 + 5 + 2 = 666.

It is an interprime number because it is at equal distance from previous prime (216521323) and next prime (216521381).

It can be written as a sum of positive squares in only one way, i.e., 135629316 + 80892036 = 11646^2 + 8994^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1503549 + ... + 1503692.

Almost surely, 2^216521352 is an apocalyptic number.

It is an amenable number.

216521352 is an abundant number, since it is smaller than the sum of its proper divisors (369890838).

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

216521352 is a wasteful number, since it uses less digits than its factorization.

216521352 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3007253 (or 3007246 counting only the distinct ones).

The product of its digits is 3600, while the sum is 27.

The square root of 216521352 is about 14714.6645221697. The cubic root of 216521352 is about 600.4823454675.

Adding to 216521352 its reverse (253125612), we get a palindrome (469646964).

The spelling of 216521352 in words is "two hundred sixteen million, five hundred twenty-one thousand, three hundred fifty-two".