77956649 has 2 divisors, whose sum is σ = 77956650. Its totient is φ = 77956648.

The previous prime is 77956631. The next prime is 77956657. The reversal of 77956649 is 94665977.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 47706649 + 30250000 = 6907^2 + 5500^2 .

It is a cyclic number.

It is not a de Polignac number, because 77956649 - 2¹⁶ = 77891113 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 77956649.

It is not a weakly prime, because it can be changed into another prime (77956609) 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, 38978324 + 38978325.

It is an arithmetic number, because the mean of its divisors is an integer number (38978325).

Almost surely, 2^77956649 is an apocalyptic number.

It is an amenable number.

77956649 is a deficient number, since it is larger than the sum of its proper divisors (1).

77956649 is an equidigital number, since it uses as much as digits as its factorization.

77956649 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2857680, while the sum is 53.

The square root of 77956649 is about 8829.3062581383. The cubic root of 77956649 is about 427.1866979340.

The spelling of 77956649 in words is "seventy-seven million, nine hundred fifty-six thousand, six hundred forty-nine".