77820937920 has 560 divisors, whose sum is σ = 315144960768. Its totient is φ = 18043914240.

The previous prime is 77820937913. The next prime is 77820937949. The reversal of 77820937920 is 2973902877.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

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 79 ways as a sum of consecutive naturals, for example, 6551827 + ... + 6563693.

Almost surely, 2^77820937920 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 77820937920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (157572480384).

77820937920 is an abundant number, since it is smaller than the sum of its proper divisors (237324022848).

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

77820937920 is a wasteful number, since it uses less digits than its factorization.

77820937920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11930 (or 11911 counting only the distinct ones).

The product of its (nonzero) digits is 2667168, while the sum is 54.

The spelling of 77820937920 in words is "seventy-seven billion, eight hundred twenty million, nine hundred thirty-seven thousand, nine hundred twenty".