72727561 has 2 divisors, whose sum is σ = 72727562. Its totient is φ = 72727560.

The previous prime is 72727553. The next prime is 72727583. The reversal of 72727561 is 16572727.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 69555600 + 3171961 = 8340^2 + 1781^2 .

It is an emirp because it is prime and its reverse (16572727) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 72727561 - 2³ = 72727553 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 72727561.

It is not a weakly prime, because it can be changed into another prime (72727511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36363780 + 36363781.

It is an arithmetic number, because the mean of its divisors is an integer number (36363781).

Almost surely, 2^72727561 is an apocalyptic number.

It is an amenable number.

72727561 is a deficient number, since it is larger than the sum of its proper divisors (1).

72727561 is an equidigital number, since it uses as much as digits as its factorization.

72727561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 41160, while the sum is 37.

The square root of 72727561 is about 8528.0455556945. The cubic root of 72727561 is about 417.4133559906.

The spelling of 72727561 in words is "seventy-two million, seven hundred twenty-seven thousand, five hundred sixty-one".