78939677 has 2 divisors, whose sum is σ = 78939678. Its totient is φ = 78939676.

The previous prime is 78939659. The next prime is 78939689. The reversal of 78939677 is 77693987.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 76230361 + 2709316 = 8731^2 + 1646^2 .

It is a cyclic number.

It is not a de Polignac number, because 78939677 - 2⁶ = 78939613 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78939697) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39469838 + 39469839.

It is an arithmetic number, because the mean of its divisors is an integer number (39469839).

Almost surely, 2^78939677 is an apocalyptic number.

It is an amenable number.

78939677 is a deficient number, since it is larger than the sum of its proper divisors (1).

78939677 is an equidigital number, since it uses as much as digits as its factorization.

78939677 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4000752, while the sum is 56.

The square root of 78939677 is about 8884.8003354043. The cubic root of 78939677 is about 428.9748012360.

The spelling of 78939677 in words is "seventy-eight million, nine hundred thirty-nine thousand, six hundred seventy-seven".