72155081 has 2 divisors, whose sum is σ = 72155082. Its totient is φ = 72155080.

The previous prime is 72155033. The next prime is 72155087. The reversal of 72155081 is 18055127.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 46308025 + 25847056 = 6805^2 + 5084^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72155081 is a prime.

It is a super-2 number, since 2×72155081² = 10412711428233122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (72155087) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36077540 + 36077541.

It is an arithmetic number, because the mean of its divisors is an integer number (36077541).

Almost surely, 2^72155081 is an apocalyptic number.

It is an amenable number.

72155081 is a deficient number, since it is larger than the sum of its proper divisors (1).

72155081 is an equidigital number, since it uses as much as digits as its factorization.

72155081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2800, while the sum is 29.

The square root of 72155081 is about 8494.4146943742. The cubic root of 72155081 is about 416.3152369743.

The spelling of 72155081 in words is "seventy-two million, one hundred fifty-five thousand, eighty-one".