72991307 has 2 divisors, whose sum is σ = 72991308. Its totient is φ = 72991306.

The previous prime is 72991301. The next prime is 72991361. The reversal of 72991307 is 70319927.

It is a weak prime.

It is an emirp because it is prime and its reverse (70319927) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 72991307 - 2⁴ = 72991291 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (72991301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36495653 + 36495654.

It is an arithmetic number, because the mean of its divisors is an integer number (36495654).

Almost surely, 2^72991307 is an apocalyptic number.

72991307 is a deficient number, since it is larger than the sum of its proper divisors (1).

72991307 is an equidigital number, since it uses as much as digits as its factorization.

72991307 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23814, while the sum is 38.

The square root of 72991307 is about 8543.4950108255. The cubic root of 72991307 is about 417.9173294839.

The spelling of 72991307 in words is "seventy-two million, nine hundred ninety-one thousand, three hundred seven".