641861889786 has 24 divisors (see below), whose sum is σ = 1497677743380. Its totient is φ = 197495966016.

The previous prime is 641861889731. The next prime is 641861889821. The reversal of 641861889786 is 687988168146.

641861889786 is a `hidden beast` number, since 6 + 418 + 61 + 8 + 89 + 78 + 6 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 621465765561 + 20396124225 = 788331^2 + 142815^2 .

It is a super-2 number, since 2×641861889786² (a number of 24 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1371499531 + ... + 1371499998.

Almost surely, 2^641861889786 is an apocalyptic number.

641861889786 is an abundant number, since it is smaller than the sum of its proper divisors (855815853594).

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

641861889786 is a wasteful number, since it uses less digits than its factorization.

641861889786 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2742999550 (or 2742999547 counting only the distinct ones).

The product of its digits is 222953472, while the sum is 72.

The spelling of 641861889786 in words is "six hundred forty-one billion, eight hundred sixty-one million, eight hundred eighty-nine thousand, seven hundred eighty-six".