77666222920 has 128 divisors (see below), whose sum is σ = 210307466880. Its totient is φ = 25433856000.

The previous prime is 77666222903. The next prime is 77666222927. The reversal of 77666222920 is 2922266677.

It is not an unprimeable number, because it can be changed into a prime (77666222927) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 68935 + ... + 400105.

It is an arithmetic number, because the mean of its divisors is an integer number (1643027085).

Almost surely, 2^77666222920 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 77666222920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (105153733440).

77666222920 is an abundant number, since it is smaller than the sum of its proper divisors (132641243960).

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

77666222920 is a wasteful number, since it uses less digits than its factorization.

77666222920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 331247 (or 331243 counting only the distinct ones).

The product of its (nonzero) digits is 1524096, while the sum is 49.

The spelling of 77666222920 in words is "seventy-seven billion, six hundred sixty-six million, two hundred twenty-two thousand, nine hundred twenty".