77121785166 has 32 divisors (see below), whose sum is σ = 166398180768. Its totient is φ = 23738557440.

The previous prime is 77121785107. The next prime is 77121785197. The reversal of 77121785166 is 66158712177.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7127575 + ... + 7138386.

It is an arithmetic number, because the mean of its divisors is an integer number (5199943149).

Almost surely, 2^77121785166 is an apocalyptic number.

77121785166 is an abundant number, since it is smaller than the sum of its proper divisors (89276395602).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

77121785166 is a wasteful number, since it uses less digits than its factorization.

77121785166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14266036.

The product of its digits is 987840, while the sum is 51.

The spelling of 77121785166 in words is "seventy-seven billion, one hundred twenty-one million, seven hundred eighty-five thousand, one hundred sixty-six".