77000081 has 2 divisors, whose sum is σ = 77000082. Its totient is φ = 77000080.

The previous prime is 77000069. The next prime is 77000083. The reversal of 77000081 is 18000077.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 73702225 + 3297856 = 8585^2 + 1816^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77000081 is a prime.

It is a super-2 number, since 2×77000081² = 11858024948013122, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 77000083, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is equal to p_4504541 and since 77000081 and 4504541 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (77000083) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38500040 + 38500041.

It is an arithmetic number, because the mean of its divisors is an integer number (38500041).

Almost surely, 2^77000081 is an apocalyptic number.

It is an amenable number.

77000081 is a deficient number, since it is larger than the sum of its proper divisors (1).

77000081 is an equidigital number, since it uses as much as digits as its factorization.

77000081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 392, while the sum is 23.

The square root of 77000081 is about 8774.9690027943. The cubic root of 77000081 is about 425.4322356889.

The spelling of 77000081 in words is "seventy-seven million, eighty-one", and thus it is an aban number and an uban number.