781278120 has 384 divisors, whose sum is σ = 3058698240. Its totient is φ = 169205760.

The previous prime is 781278097. The next prime is 781278139. The reversal of 781278120 is 21872187.

It is a happy number.

781278120 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×781278120² = 1220791001581468800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 5702692 + ... + 5702828.

It is an arithmetic number, because the mean of its divisors is an integer number (7965360).

Almost surely, 2^781278120 is an apocalyptic number.

781278120 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 781278120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1529349120).

781278120 is an abundant number, since it is smaller than the sum of its proper divisors (2277420120).

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

781278120 is a wasteful number, since it uses less digits than its factorization.

781278120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 265 (or 258 counting only the distinct ones).

The product of its (nonzero) digits is 12544, while the sum is 36.

The square root of 781278120 is about 27951.3527400732. The cubic root of 781278120 is about 921.0189246572.

The spelling of 781278120 in words is "seven hundred eighty-one million, two hundred seventy-eight thousand, one hundred twenty".