77977966 has 20 divisors (see below), whose sum is σ = 128711160. Its totient is φ = 35431220.

The previous prime is 77977937. The next prime is 77977967. The reversal of 77977966 is 66977977.

It is a self number, because there is not a number n which added to its sum of digits gives 77977966.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77977967) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 27951 + ... + 30613.

It is an arithmetic number, because the mean of its divisors is an integer number (6435558).

Almost surely, 2^77977966 is an apocalyptic number.

77977966 is a deficient number, since it is larger than the sum of its proper divisors (50733194).

77977966 is an equidigital number, since it uses as much as digits as its factorization.

77977966 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2709 (or 2676 counting only the distinct ones).

The product of its digits is 7001316, while the sum is 58.

The square root of 77977966 is about 8830.5133486112. The cubic root of 77977966 is about 427.2256320042.

The spelling of 77977966 in words is "seventy-seven million, nine hundred seventy-seven thousand, nine hundred sixty-six".