78746939 has 2 divisors, whose sum is σ = 78746940. Its totient is φ = 78746938.

The previous prime is 78746911. The next prime is 78746957. The reversal of 78746939 is 93964787.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78746939 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (78746959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39373469 + 39373470.

It is an arithmetic number, because the mean of its divisors is an integer number (39373470).

Almost surely, 2^78746939 is an apocalyptic number.

78746939 is a deficient number, since it is larger than the sum of its proper divisors (1).

78746939 is an equidigital number, since it uses as much as digits as its factorization.

78746939 is an evil number, because the sum of its binary digits is even.

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

The square root of 78746939 is about 8873.9472051619. The cubic root of 78746939 is about 428.6253904381.

The spelling of 78746939 in words is "seventy-eight million, seven hundred forty-six thousand, nine hundred thirty-nine".