77993397956 has 6 divisors (see below), whose sum is σ = 136488446430. Its totient is φ = 38996698976.

The previous prime is 77993397899. The next prime is 77993397971. The reversal of 77993397956 is 65979339977.

It can be written as a sum of positive squares in only one way, i.e., 64931193856 + 13062204100 = 254816^2 + 114290^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9749174741 + ... + 9749174748.

It is an arithmetic number, because the mean of its divisors is an integer number (22748074405).

Almost surely, 2^77993397956 is an apocalyptic number.

It is an amenable number.

77993397956 is a deficient number, since it is larger than the sum of its proper divisors (58495048474).

77993397956 is a wasteful number, since it uses less digits than its factorization.

77993397956 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19498349493 (or 19498349491 counting only the distinct ones).

The product of its digits is 607614210, while the sum is 74.

The spelling of 77993397956 in words is "seventy-seven billion, nine hundred ninety-three million, three hundred ninety-seven thousand, nine hundred fifty-six".