781894840636 has 36 divisors (see below), whose sum is σ = 1714154079288. Its totient is φ = 309321034848.

The previous prime is 781894840483. The next prime is 781894840673. The reversal of 781894840636 is 636048498187.

It is a super-2 number, since 2×781894840636² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 153430506 + ... + 153435601.

Almost surely, 2^781894840636 is an apocalyptic number.

It is an amenable number.

781894840636 is an abundant number, since it is smaller than the sum of its proper divisors (932259238652).

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

781894840636 is a wasteful number, since it uses less digits than its factorization.

781894840636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 306866138 (or 306866129 counting only the distinct ones).

The product of its (nonzero) digits is 55738368, while the sum is 64.

The spelling of 781894840636 in words is "seven hundred eighty-one billion, eight hundred ninety-four million, eight hundred forty thousand, six hundred thirty-six".