77857973 has 2 divisors, whose sum is σ = 77857974. Its totient is φ = 77857972.

The previous prime is 77857951. The next prime is 77857979. The reversal of 77857973 is 37975877.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 77123524 + 734449 = 8782^2 + 857^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77857973 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77857979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38928986 + 38928987.

It is an arithmetic number, because the mean of its divisors is an integer number (38928987).

Almost surely, 2^77857973 is an apocalyptic number.

It is an amenable number.

77857973 is a deficient number, since it is larger than the sum of its proper divisors (1).

77857973 is an equidigital number, since it uses as much as digits as its factorization.

77857973 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2593080, while the sum is 53.

The square root of 77857973 is about 8823.7165072321. The cubic root of 77857973 is about 427.0063803122.

The spelling of 77857973 in words is "seventy-seven million, eight hundred fifty-seven thousand, nine hundred seventy-three".