78685049 has 2 divisors, whose sum is σ = 78685050. Its totient is φ = 78685048.

The previous prime is 78684997. The next prime is 78685063. The reversal of 78685049 is 94058687.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 74304400 + 4380649 = 8620^2 + 2093^2 .

It is a cyclic number.

It is not a de Polignac number, because 78685049 - 2²⁰ = 77636473 is a prime.

It is a super-2 number, since 2×78685049² = 12382673872264802, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 78684994 and 78685012.

It is not a weakly prime, because it can be changed into another prime (78685249) 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, 39342524 + 39342525.

It is an arithmetic number, because the mean of its divisors is an integer number (39342525).

Almost surely, 2^78685049 is an apocalyptic number.

It is an amenable number.

78685049 is a deficient number, since it is larger than the sum of its proper divisors (1).

78685049 is an equidigital number, since it uses as much as digits as its factorization.

78685049 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 483840, while the sum is 47.

The square root of 78685049 is about 8870.4593454905. The cubic root of 78685049 is about 428.5130703977.

The spelling of 78685049 in words is "seventy-eight million, six hundred eighty-five thousand, forty-nine".