78799997 has 2 divisors, whose sum is σ = 78799998. Its totient is φ = 78799996.

The previous prime is 78799993. The next prime is 78800017. The reversal of 78799997 is 79999787.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 72914521 + 5885476 = 8539^2 + 2426^2 .

It is a cyclic number.

It is not a de Polignac number, because 78799997 - 2² = 78799993 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78799993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39399998 + 39399999.

It is an arithmetic number, because the mean of its divisors is an integer number (39399999).

Almost surely, 2^78799997 is an apocalyptic number.

It is an amenable number.

78799997 is a deficient number, since it is larger than the sum of its proper divisors (1).

78799997 is an equidigital number, since it uses as much as digits as its factorization.

78799997 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18003384, while the sum is 65.

The square root of 78799997 is about 8876.9362394916. The cubic root of 78799997 is about 428.7216350265.

The spelling of 78799997 in words is "seventy-eight million, seven hundred ninety-nine thousand, nine hundred ninety-seven".