780138920 has 64 divisors (see below), whose sum is σ = 1922616000. Its totient is φ = 282542080.

The previous prime is 780138913. The next prime is 780138923. The reversal of 780138920 is 29831087.

It is not an unprimeable number, because it can be changed into a prime (780138923) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 109631 + ... + 116529.

It is an arithmetic number, because the mean of its divisors is an integer number (30040875).

Almost surely, 2^780138920 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 780138920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (961308000).

780138920 is an abundant number, since it is smaller than the sum of its proper divisors (1142477080).

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

780138920 is a wasteful number, since it uses less digits than its factorization.

780138920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7178 (or 7174 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 38.

The square root of 780138920 is about 27930.9670437670. The cubic root of 780138920 is about 920.5710537851.

The spelling of 780138920 in words is "seven hundred eighty million, one hundred thirty-eight thousand, nine hundred twenty".