77648939 has 2 divisors, whose sum is σ = 77648940. Its totient is φ = 77648938.

The previous prime is 77648933. The next prime is 77648981. The reversal of 77648939 is 93984677.

It is a weak prime.

It is an emirp because it is prime and its reverse (93984677) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 77648939 - 2¹² = 77644843 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (77648933) 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, 38824469 + 38824470.

It is an arithmetic number, because the mean of its divisors is an integer number (38824470).

Almost surely, 2^77648939 is an apocalyptic number.

77648939 is a deficient number, since it is larger than the sum of its proper divisors (1).

77648939 is an equidigital number, since it uses as much as digits as its factorization.

77648939 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2286144, while the sum is 53.

The square root of 77648939 is about 8811.8635373002. The cubic root of 77648939 is about 426.6238938920.

It can be divided in two parts, 77648 and 939, that added together give a palindrome (78587).

The spelling of 77648939 in words is "seventy-seven million, six hundred forty-eight thousand, nine hundred thirty-nine".