191851634840 has 64 divisors (see below), whose sum is σ = 448674478560. Its totient is φ = 73766937600.

The previous prime is 191851634801. The next prime is 191851634869. The reversal of 191851634840 is 48436158191.

191851634840 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a hoax number, since the sum of its digits (50) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 658061 + ... + 903740.

Almost surely, 2^191851634840 is an apocalyptic number.

191851634840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

191851634840 is an abundant number, since it is smaller than the sum of its proper divisors (256822843720).

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

191851634840 is a wasteful number, since it uses less digits than its factorization.

191851634840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1561932 (or 1561928 counting only the distinct ones).

The product of its (nonzero) digits is 829440, while the sum is 50.

The spelling of 191851634840 in words is "one hundred ninety-one billion, eight hundred fifty-one million, six hundred thirty-four thousand, eight hundred forty".