77993578643 has 2 divisors, whose sum is σ = 77993578644. Its totient is φ = 77993578642.

The previous prime is 77993578633. The next prime is 77993578679. The reversal of 77993578643 is 34687539977.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 77993578643 - 2²⁸ = 77725143187 is a prime.

It is not a weakly prime, because it can be changed into another prime (77993578613) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38996789321 + 38996789322.

It is an arithmetic number, because the mean of its divisors is an integer number (38996789322).

Almost surely, 2^77993578643 is an apocalyptic number.

77993578643 is a deficient number, since it is larger than the sum of its proper divisors (1).

77993578643 is an equidigital number, since it uses as much as digits as its factorization.

77993578643 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 240045120, while the sum is 68.

The spelling of 77993578643 in words is "seventy-seven billion, nine hundred ninety-three million, five hundred seventy-eight thousand, six hundred forty-three".