72161237 has 2 divisors, whose sum is σ = 72161238. Its totient is φ = 72161236.

The previous prime is 72161233. The next prime is 72161269. The reversal of 72161237 is 73216127.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 54302161 + 17859076 = 7369^2 + 4226^2 .

It is a cyclic number.

It is not a de Polignac number, because 72161237 - 2² = 72161233 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72161233) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36080618 + 36080619.

It is an arithmetic number, because the mean of its divisors is an integer number (36080619).

Almost surely, 2^72161237 is an apocalyptic number.

It is an amenable number.

72161237 is a deficient number, since it is larger than the sum of its proper divisors (1).

72161237 is an equidigital number, since it uses as much as digits as its factorization.

72161237 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3528, while the sum is 29.

The square root of 72161237 is about 8494.7770423949. Note that the first 3 decimals coincide. The cubic root of 72161237 is about 416.3270761208.

The spelling of 72161237 in words is "seventy-two million, one hundred sixty-one thousand, two hundred thirty-seven".