778977920 has 256 divisors, whose sum is σ = 2256076800. Its totient is φ = 251596800.

The previous prime is 778977911. The next prime is 778977923. The reversal of 778977920 is 29779877.

It is a Harshad number since it is a multiple of its sum of digits (56).

It is not an unprimeable number, because it can be changed into a prime (778977923) 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, 9860441 + ... + 9860519.

It is an arithmetic number, because the mean of its divisors is an integer number (8812800).

Almost surely, 2^778977920 is an apocalyptic number.

778977920 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 778977920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1128038400).

778977920 is an abundant number, since it is smaller than the sum of its proper divisors (1477098880).

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

778977920 is a wasteful number, since it uses less digits than its factorization.

778977920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 207 (or 195 counting only the distinct ones).

The product of its (nonzero) digits is 3111696, while the sum is 56.

The square root of 778977920 is about 27910.1759220539. The cubic root of 778977920 is about 920.1141635265.

The spelling of 778977920 in words is "seven hundred seventy-eight million, nine hundred seventy-seven thousand, nine hundred twenty".