77685493 has 2 divisors, whose sum is σ = 77685494. Its totient is φ = 77685492.

The previous prime is 77685469. The next prime is 77685523. The reversal of 77685493 is 39458677.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 62615569 + 15069924 = 7913^2 + 3882^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77685493 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77685193) 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, 38842746 + 38842747.

It is an arithmetic number, because the mean of its divisors is an integer number (38842747).

Almost surely, 2^77685493 is an apocalyptic number.

It is an amenable number.

77685493 is a deficient number, since it is larger than the sum of its proper divisors (1).

77685493 is an equidigital number, since it uses as much as digits as its factorization.

77685493 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1270080, while the sum is 49.

The square root of 77685493 is about 8813.9374288680. The cubic root of 77685493 is about 426.6908291845.

The spelling of 77685493 in words is "seventy-seven million, six hundred eighty-five thousand, four hundred ninety-three".