77949649 has 2 divisors, whose sum is σ = 77949650. Its totient is φ = 77949648.

The previous prime is 77949631. The next prime is 77949653. The reversal of 77949649 is 94694977.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 62489025 + 15460624 = 7905^2 + 3932^2 .

It is a cyclic number.

It is not a de Polignac number, because 77949649 - 2¹⁷ = 77818577 is a prime.

It is a super-2 number, since 2×77949649² = 12152295558446402, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 77949649.

It is not a weakly prime, because it can be changed into another prime (77949629) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38974824 + 38974825.

It is an arithmetic number, because the mean of its divisors is an integer number (38974825).

Almost surely, 2^77949649 is an apocalyptic number.

It is an amenable number.

77949649 is a deficient number, since it is larger than the sum of its proper divisors (1).

77949649 is an equidigital number, since it uses as much as digits as its factorization.

77949649 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3429216, while the sum is 55.

The square root of 77949649 is about 8828.9098421040. The cubic root of 77949649 is about 427.1739113556.

The spelling of 77949649 in words is "seventy-seven million, nine hundred forty-nine thousand, six hundred forty-nine".