77979487 has 2 divisors, whose sum is σ = 77979488. Its totient is φ = 77979486.

The previous prime is 77979449. The next prime is 77979497. The reversal of 77979487 is 78497977.

It is a strong prime.

It is an emirp because it is prime and its reverse (78497977) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 77979487 - 2⁷ = 77979359 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77979497) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38989743 + 38989744.

It is an arithmetic number, because the mean of its divisors is an integer number (38989744).

Almost surely, 2^77979487 is an apocalyptic number.

77979487 is a deficient number, since it is larger than the sum of its proper divisors (1).

77979487 is an equidigital number, since it uses as much as digits as its factorization.

77979487 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6223392, while the sum is 58.

The square root of 77979487 is about 8830.5994700247. The cubic root of 77979487 is about 427.2284097374.

The spelling of 77979487 in words is "seventy-seven million, nine hundred seventy-nine thousand, four hundred eighty-seven".