77391899989 has 4 divisors (see below), whose sum is σ = 77904429280. Its totient is φ = 76879370700.

The previous prime is 77391899987. The next prime is 77391900007. The reversal of 77391899989 is 98999819377.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 77391899989 - 2¹ = 77391899987 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77391899987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 256264419 + ... + 256264720.

It is an arithmetic number, because the mean of its divisors is an integer number (19476107320).

Almost surely, 2^77391899989 is an apocalyptic number.

It is an amenable number.

77391899989 is a deficient number, since it is larger than the sum of its proper divisors (512529291).

77391899989 is a wasteful number, since it uses less digits than its factorization.

77391899989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 512529290.

The product of its digits is 555532992, while the sum is 79.

The spelling of 77391899989 in words is "seventy-seven billion, three hundred ninety-one million, eight hundred ninety-nine thousand, nine hundred eighty-nine".