72556381 has 2 divisors, whose sum is σ = 72556382. Its totient is φ = 72556380.

The previous prime is 72556361. The next prime is 72556387. The reversal of 72556381 is 18365527.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 67076100 + 5480281 = 8190^2 + 2341^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72556381 is a prime.

It is a super-2 number, since 2×72556381² = 10528856847634322, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 72556381.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72556387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36278190 + 36278191.

It is an arithmetic number, because the mean of its divisors is an integer number (36278191).

Almost surely, 2^72556381 is an apocalyptic number.

It is an amenable number.

72556381 is a deficient number, since it is larger than the sum of its proper divisors (1).

72556381 is an equidigital number, since it uses as much as digits as its factorization.

72556381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 50400, while the sum is 37.

The square root of 72556381 is about 8518.0033458552. The cubic root of 72556381 is about 417.0856079283.

The spelling of 72556381 in words is "seventy-two million, five hundred fifty-six thousand, three hundred eighty-one".