78922691 has 2 divisors, whose sum is σ = 78922692. Its totient is φ = 78922690.

The previous prime is 78922667. The next prime is 78922763. The reversal of 78922691 is 19622987.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78922691 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 (78922631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39461345 + 39461346.

It is an arithmetic number, because the mean of its divisors is an integer number (39461346).

Almost surely, 2^78922691 is an apocalyptic number.

78922691 is a deficient number, since it is larger than the sum of its proper divisors (1).

78922691 is an equidigital number, since it uses as much as digits as its factorization.

78922691 is an evil number, because the sum of its binary digits is even.

The product of its digits is 108864, while the sum is 44.

The square root of 78922691 is about 8883.8443817978. The cubic root of 78922691 is about 428.9440305304.

The spelling of 78922691 in words is "seventy-eight million, nine hundred twenty-two thousand, six hundred ninety-one".