781991422836 has 48 divisors (see below), whose sum is σ = 1965906734400. Its totient is φ = 240502217472.

The previous prime is 781991422831. The next prime is 781991422847. The reversal of 781991422836 is 638224199187.

It is a super-2 number, since 2×781991422836² (a number of 25 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 781991422836.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (781991422831) 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, 810321 + ... + 1490168.

It is an arithmetic number, because the mean of its divisors is an integer number (40956390300).

Almost surely, 2^781991422836 is an apocalyptic number.

It is an amenable number.

781991422836 is an abundant number, since it is smaller than the sum of its proper divisors (1183915311564).

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

781991422836 is a wasteful number, since it uses less digits than its factorization.

781991422836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2302688 (or 2302686 counting only the distinct ones).

The product of its digits is 10450944, while the sum is 60.

The spelling of 781991422836 in words is "seven hundred eighty-one billion, nine hundred ninety-one million, four hundred twenty-two thousand, eight hundred thirty-six".