72825561 has 20 divisors (see below), whose sum is σ = 109438692. Its totient is φ = 48260448.

The previous prime is 72825547. The next prime is 72825589. The reversal of 72825561 is 16552827.

It is a happy number.

72825561 is a `hidden beast` number, since 72 + 8 + 25 + 561 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 51840000 + 20985561 = 7200^2 + 4581^2 .

It is not a de Polignac number, because 72825561 - 2¹⁰ = 72824537 is a prime.

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 Curzon number.

It is not an unprimeable number, because it can be changed into a prime (72821561) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 11415 + ... + 16611.

Almost surely, 2^72825561 is an apocalyptic number.

It is an amenable number.

72825561 is a deficient number, since it is larger than the sum of its proper divisors (36613131).

72825561 is a wasteful number, since it uses less digits than its factorization.

72825561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5382 (or 5373 counting only the distinct ones).

The product of its digits is 33600, while the sum is 36.

The square root of 72825561 is about 8533.7893693247. The cubic root of 72825561 is about 417.6007592634.

The spelling of 72825561 in words is "seventy-two million, eight hundred twenty-five thousand, five hundred sixty-one".