72170977 has 2 divisors, whose sum is σ = 72170978. Its totient is φ = 72170976.

The previous prime is 72170951. The next prime is 72171013. The reversal of 72170977 is 77907127.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 71978256 + 192721 = 8484^2 + 439^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72170977 is a prime.

It is a super-2 number, since 2×72170977² = 10417299842269058, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (72170927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36085488 + 36085489.

It is an arithmetic number, because the mean of its divisors is an integer number (36085489).

Almost surely, 2^72170977 is an apocalyptic number.

It is an amenable number.

72170977 is a deficient number, since it is larger than the sum of its proper divisors (1).

72170977 is an equidigital number, since it uses as much as digits as its factorization.

72170977 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 43218, while the sum is 40.

The square root of 72170977 is about 8495.3503164967. The cubic root of 72170977 is about 416.3458065984.

The spelling of 72170977 in words is "seventy-two million, one hundred seventy thousand, nine hundred seventy-seven".