2172564 has 36 divisors (see below), whose sum is σ = 5683860. Its totient is φ = 698880.

The previous prime is 2172563. The next prime is 2172571. The reversal of 2172564 is 4652712.

It can be written as a sum of positive squares in 2 ways, for example, as 980100 + 1192464 = 990^2 + 1092^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2172563) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4 + ... + 2084.

It is an arithmetic number, because the mean of its divisors is an integer number (157885).

2^2172564 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 2172564, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2841930).

2172564 is an abundant number, since it is smaller than the sum of its proper divisors (3511296).

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

2172564 is a wasteful number, since it uses less digits than its factorization.

2172564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2120 (or 2115 counting only the distinct ones).

The product of its digits is 3360, while the sum is 27.

The square root of 2172564 is about 1473.9620076515. The cubic root of 2172564 is about 129.5162295864.

The spelling of 2172564 in words is "two million, one hundred seventy-two thousand, five hundred sixty-four".