191821012 has 12 divisors (see below), whose sum is σ = 350282016. Its totient is φ = 91740440.

The previous prime is 191821009. The next prime is 191821037. The reversal of 191821012 is 210128191.

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 3 ways as a sum of consecutive naturals, for example, 1042414 + ... + 1042597.

It is an arithmetic number, because the mean of its divisors is an integer number (29190168).

Almost surely, 2^191821012 is an apocalyptic number.

It is an amenable number.

191821012 is a deficient number, since it is larger than the sum of its proper divisors (158461004).

191821012 is a wasteful number, since it uses less digits than its factorization.

191821012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2085038 (or 2085036 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 25.

The square root of 191821012 is about 13849.9462814843. The cubic root of 191821012 is about 576.7205047726.

The spelling of 191821012 in words is "one hundred ninety-one million, eight hundred twenty-one thousand, twelve".