72761561 has 2 divisors, whose sum is σ = 72761562. Its totient is φ = 72761560.

The previous prime is 72761539. The next prime is 72761567. The reversal of 72761561 is 16516727.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 41847961 + 30913600 = 6469^2 + 5560^2 .

It is a cyclic number.

It is not a de Polignac number, because 72761561 - 2¹⁴ = 72745177 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (72761567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36380780 + 36380781.

It is an arithmetic number, because the mean of its divisors is an integer number (36380781).

Almost surely, 2^72761561 is an apocalyptic number.

It is an amenable number.

72761561 is a deficient number, since it is larger than the sum of its proper divisors (1).

72761561 is an equidigital number, since it uses as much as digits as its factorization.

72761561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 17640, while the sum is 35.

The square root of 72761561 is about 8530.0387455158. The cubic root of 72761561 is about 417.4783925136.

The spelling of 72761561 in words is "seventy-two million, seven hundred sixty-one thousand, five hundred sixty-one".