72175561 has 2 divisors, whose sum is σ = 72175562. Its totient is φ = 72175560.

The previous prime is 72175553. The next prime is 72175583. The reversal of 72175561 is 16557127.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 70896400 + 1279161 = 8420^2 + 1131^2 .

It is a cyclic number.

It is not a de Polignac number, because 72175561 - 2³ = 72175553 is a prime.

It is not a weakly prime, because it can be changed into another prime (72175501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36087780 + 36087781.

It is an arithmetic number, because the mean of its divisors is an integer number (36087781).

Almost surely, 2^72175561 is an apocalyptic number.

It is an amenable number.

72175561 is a deficient number, since it is larger than the sum of its proper divisors (1).

72175561 is an equidigital number, since it uses as much as digits as its factorization.

72175561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 14700, while the sum is 34.

The square root of 72175561 is about 8495.6201068551. The cubic root of 72175561 is about 416.3546212625.

The spelling of 72175561 in words is "seventy-two million, one hundred seventy-five thousand, five hundred sixty-one".