77699989 has 2 divisors, whose sum is σ = 77699990. Its totient is φ = 77699988.

The previous prime is 77699983. The next prime is 77700001. The reversal of 77699989 is 98999677.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 74960964 + 2739025 = 8658^2 + 1655^2 .

It is a cyclic number.

It is not a de Polignac number, because 77699989 - 2²⁵ = 44145557 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 77699989.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77699983) 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, 38849994 + 38849995.

It is an arithmetic number, because the mean of its divisors is an integer number (38849995).

Almost surely, 2^77699989 is an apocalyptic number.

It is an amenable number.

77699989 is a deficient number, since it is larger than the sum of its proper divisors (1).

77699989 is an equidigital number, since it uses as much as digits as its factorization.

77699989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15431472, while the sum is 64.

The square root of 77699989 is about 8814.7597244621. The cubic root of 77699989 is about 426.7173674966.

The spelling of 77699989 in words is "seventy-seven million, six hundred ninety-nine thousand, nine hundred eighty-nine".