78692891 has 2 divisors, whose sum is σ = 78692892. Its totient is φ = 78692890.

The previous prime is 78692857. The next prime is 78692897. The reversal of 78692891 is 19829687.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78692891 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (78692897) 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, 39346445 + 39346446.

It is an arithmetic number, because the mean of its divisors is an integer number (39346446).

Almost surely, 2^78692891 is an apocalyptic number.

78692891 is a deficient number, since it is larger than the sum of its proper divisors (1).

78692891 is an equidigital number, since it uses as much as digits as its factorization.

78692891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 435456, while the sum is 50.

The square root of 78692891 is about 8870.9013634467. The cubic root of 78692891 is about 428.5273055792.

The spelling of 78692891 in words is "seventy-eight million, six hundred ninety-two thousand, eight hundred ninety-one".