72561564 has 18 divisors (see below), whose sum is σ = 183419600. Its totient is φ = 24187176.

The previous prime is 72561557. The next prime is 72561571. The reversal of 72561564 is 46516527.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (72561557) and next prime (72561571).

It is a tau number, because it is divible by the number of its divisors (18).

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 2015599 = 72561564 / (7 + 2 + 5 + 6 + 1 + 5 + 6 + 4).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1007764 + ... + 1007835.

Almost surely, 2^72561564 is an apocalyptic number.

It is an amenable number.

72561564 is an abundant number, since it is smaller than the sum of its proper divisors (110858036).

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

72561564 is a wasteful number, since it uses less digits than its factorization.

72561564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2015609 (or 2015604 counting only the distinct ones).

The product of its digits is 50400, while the sum is 36.

The square root of 72561564 is about 8518.3075783867. The cubic root of 72561564 is about 417.0955390706.

The spelling of 72561564 in words is "seventy-two million, five hundred sixty-one thousand, five hundred sixty-four".