215453664 has 72 divisors (see below), whose sum is σ = 629286840. Its totient is φ = 69873408.

The previous prime is 215453653. The next prime is 215453677. The reversal of 215453664 is 466354512.

215453664 is a `hidden beast` number, since 21 + 545 + 36 + 64 = 666.

It is a tau number, because it is divible by the number of its divisors (72).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 547 + ... + 20765.

It is an arithmetic number, because the mean of its divisors is an integer number (8740095).

Almost surely, 2^215453664 is an apocalyptic number.

215453664 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 215453664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (314643420).

215453664 is an abundant number, since it is smaller than the sum of its proper divisors (413833176).

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

215453664 is a wasteful number, since it uses less digits than its factorization.

215453664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20272 (or 20261 counting only the distinct ones).

The product of its digits is 86400, while the sum is 36.

The square root of 215453664 is about 14678.3399606359. The cubic root of 215453664 is about 599.4937062312.

The spelling of 215453664 in words is "two hundred fifteen million, four hundred fifty-three thousand, six hundred sixty-four".