72356561 has 2 divisors, whose sum is σ = 72356562. Its totient is φ = 72356560.

The previous prime is 72356507. The next prime is 72356563. The reversal of 72356561 is 16565327.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 64963600 + 7392961 = 8060^2 + 2719^2 .

It is a cyclic number.

It is not a de Polignac number, because 72356561 - 2²² = 68162257 is a prime.

Together with 72356563, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (72356563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36178280 + 36178281.

It is an arithmetic number, because the mean of its divisors is an integer number (36178281).

Almost surely, 2^72356561 is an apocalyptic number.

It is an amenable number.

72356561 is a deficient number, since it is larger than the sum of its proper divisors (1).

72356561 is an equidigital number, since it uses as much as digits as its factorization.

72356561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 37800, while the sum is 35.

The square root of 72356561 is about 8506.2659845552. The cubic root of 72356561 is about 416.7023718380.

The spelling of 72356561 in words is "seventy-two million, three hundred fifty-six thousand, five hundred sixty-one".