72259981 has 2 divisors, whose sum is σ = 72259982. Its totient is φ = 72259980.

The previous prime is 72259963. The next prime is 72259987. The reversal of 72259981 is 18995227.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 57244356 + 15015625 = 7566^2 + 3875^2 .

It is a cyclic number.

It is not a de Polignac number, because 72259981 - 2¹⁵ = 72227213 is a prime.

It is a super-2 number, since 2×72259981² = 10443009708240722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72259987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36129990 + 36129991.

It is an arithmetic number, because the mean of its divisors is an integer number (36129991).

Almost surely, 2^72259981 is an apocalyptic number.

It is an amenable number.

72259981 is a deficient number, since it is larger than the sum of its proper divisors (1).

72259981 is an equidigital number, since it uses as much as digits as its factorization.

72259981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 90720, while the sum is 43.

The square root of 72259981 is about 8500.5870973716. The cubic root of 72259981 is about 416.5168874631.

The spelling of 72259981 in words is "seventy-two million, two hundred fifty-nine thousand, nine hundred eighty-one".