2172305664 has 81 divisors (see below), whose sum is σ = 6269749759. Its totient is φ = 723356160.

The previous prime is 2172305657. The next prime is 2172305669. The reversal of 2172305664 is 4665032712.

The square root of 2172305664 is 46608.

It is a perfect power (a square), and thus also a powerful number.

2172305664 is a `hidden beast` number, since 21 + 72 + 3 + 0 + 566 + 4 = 666.

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

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2172305669) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 2236699 + ... + 2237669.

Almost surely, 2^2172305664 is an apocalyptic number.

2172305664 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

2172305664 is the 46608-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2172305664

2172305664 is an abundant number, since it is smaller than the sum of its proper divisors (4097444095).

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

2172305664 is an frugal number, since it uses more digits than its factorization.

2172305664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1964 (or 976 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 36.

The cubic root of 2172305664 is about 1295.1109586256.

Multiplying 2172305664 by its sum of digits (36), we get a square (78203003904 = 279648²).

2172305664 divided by its sum of digits (36) gives a square (60341824 = 7768²).

The spelling of 2172305664 in words is "two billion, one hundred seventy-two million, three hundred five thousand, six hundred sixty-four".