77076721 has 2 divisors, whose sum is σ = 77076722. Its totient is φ = 77076720.

The previous prime is 77076719. The next prime is 77076731. The reversal of 77076721 is 12767077.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 66585600 + 10491121 = 8160^2 + 3239^2 .

It is a cyclic number.

It is not a de Polignac number, because 77076721 - 2¹ = 77076719 is a prime.

It is a super-2 number, since 2×77076721² = 11881641840223682, which contains 22 as substring.

Together with 77076719, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p_4508758 and since 77076721 and 4508758 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 (77076731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38538360 + 38538361.

It is an arithmetic number, because the mean of its divisors is an integer number (38538361).

Almost surely, 2^77076721 is an apocalyptic number.

It is an amenable number.

77076721 is a deficient number, since it is larger than the sum of its proper divisors (1).

77076721 is an equidigital number, since it uses as much as digits as its factorization.

77076721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 28812, while the sum is 37.

The square root of 77076721 is about 8779.3348836914. The cubic root of 77076721 is about 425.5733364711.

The spelling of 77076721 in words is "seventy-seven million, seventy-six thousand, seven hundred twenty-one".