72991747 has 2 divisors, whose sum is σ = 72991748. Its totient is φ = 72991746.

The previous prime is 72991733. The next prime is 72991771. The reversal of 72991747 is 74719927.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 72991747 - 2⁷ = 72991619 is a prime.

It is a super-2 number, since 2×72991747² = 10655590260224018, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 72991697 and 72991706.

It is not a weakly prime, because it can be changed into another prime (72991147) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36495873 + 36495874.

It is an arithmetic number, because the mean of its divisors is an integer number (36495874).

Almost surely, 2^72991747 is an apocalyptic number.

72991747 is a deficient number, since it is larger than the sum of its proper divisors (1).

72991747 is an equidigital number, since it uses as much as digits as its factorization.

72991747 is an evil number, because the sum of its binary digits is even.

The product of its digits is 222264, while the sum is 46.

The square root of 72991747 is about 8543.5207613723. The cubic root of 72991747 is about 417.9181692334.

The spelling of 72991747 in words is "seventy-two million, nine hundred ninety-one thousand, seven hundred forty-seven".