72971291 has 2 divisors, whose sum is σ = 72971292. Its totient is φ = 72971290.

The previous prime is 72971263. The next prime is 72971299. The reversal of 72971291 is 19217927.

It is a strong prime.

It is an emirp because it is prime and its reverse (19217927) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72971291 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (72971299) 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, 36485645 + 36485646.

It is an arithmetic number, because the mean of its divisors is an integer number (36485646).

Almost surely, 2^72971291 is an apocalyptic number.

72971291 is a deficient number, since it is larger than the sum of its proper divisors (1).

72971291 is an equidigital number, since it uses as much as digits as its factorization.

72971291 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15876, while the sum is 38.

The square root of 72971291 is about 8542.3235129559. The cubic root of 72971291 is about 417.8791249434.

The spelling of 72971291 in words is "seventy-two million, nine hundred seventy-one thousand, two hundred ninety-one".