216645252 has 12 divisors (see below), whose sum is σ = 505505616. Its totient is φ = 72215080.

The previous prime is 216645251. The next prime is 216645269. The reversal of 216645252 is 252546612.

It is a tau number, because it is divible by the number of its divisors (12).

It is not an unprimeable number, because it can be changed into a prime (216645251) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9026874 + ... + 9026897.

It is an arithmetic number, because the mean of its divisors is an integer number (42125468).

Almost surely, 2^216645252 is an apocalyptic number.

It is an amenable number.

216645252 is an abundant number, since it is smaller than the sum of its proper divisors (288860364).

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

216645252 is a wasteful number, since it uses less digits than its factorization.

216645252 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18053778 (or 18053776 counting only the distinct ones).

The product of its digits is 28800, while the sum is 33.

The square root of 216645252 is about 14718.8740058471. The cubic root of 216645252 is about 600.5968616190.

The spelling of 216645252 in words is "two hundred sixteen million, six hundred forty-five thousand, two hundred fifty-two".