76720817 has 2 divisors, whose sum is σ = 76720818. Its totient is φ = 76720816.

The previous prime is 76720811. The next prime is 76720867. The reversal of 76720817 is 71802767.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 75620416 + 1100401 = 8696^2 + 1049^2 .

It is a cyclic number.

It is not a de Polignac number, because 76720817 - 2¹² = 76716721 is a prime.

It is a super-2 number, since 2×76720817² = 11772167522294978, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (76720811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38360408 + 38360409.

It is an arithmetic number, because the mean of its divisors is an integer number (38360409).

Almost surely, 2^76720817 is an apocalyptic number.

It is an amenable number.

76720817 is a deficient number, since it is larger than the sum of its proper divisors (1).

76720817 is an equidigital number, since it uses as much as digits as its factorization.

76720817 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32928, while the sum is 38.

The square root of 76720817 is about 8759.0420138278. The cubic root of 76720817 is about 424.9172932485.

The spelling of 76720817 in words is "seventy-six million, seven hundred twenty thousand, eight hundred seventeen".