781995816 has 128 divisors (see below), whose sum is σ = 2492006400. Its totient is φ = 222575040.

The previous prime is 781995763. The next prime is 781995827. The reversal of 781995816 is 618599187.

781995816 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 2×781995816² = 1223034912483011712, which contains 22 as substring.

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

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 469401 + ... + 471063.

It is an arithmetic number, because the mean of its divisors is an integer number (19468800).

Almost surely, 2^781995816 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 781995816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1246003200).

781995816 is an abundant number, since it is smaller than the sum of its proper divisors (1710010584).

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

781995816 is a wasteful number, since it uses less digits than its factorization.

781995816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1996 (or 1986 counting only the distinct ones).

The product of its digits is 1088640, while the sum is 54.

The square root of 781995816 is about 27964.1880983518. The cubic root of 781995816 is about 921.3008598088.

The spelling of 781995816 in words is "seven hundred eighty-one million, nine hundred ninety-five thousand, eight hundred sixteen".