191953021 has 16 divisors (see below), whose sum is σ = 214361280. Its totient is φ = 170743680.

The previous prime is 191952949. The next prime is 191953051. The reversal of 191953021 is 120359191.

It is a happy number.

It is not a de Polignac number, because 191953021 - 2²⁵ = 158398589 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (191953051) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 42070 + ... + 46408.

It is an arithmetic number, because the mean of its divisors is an integer number (13397580).

Almost surely, 2^191953021 is an apocalyptic number.

It is an amenable number.

191953021 is a deficient number, since it is larger than the sum of its proper divisors (22408259).

191953021 is a wasteful number, since it uses less digits than its factorization.

191953021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4476.

The product of its (nonzero) digits is 2430, while the sum is 31.

The square root of 191953021 is about 13854.7111481979. The cubic root of 191953021 is about 576.8527718941.

The spelling of 191953021 in words is "one hundred ninety-one million, nine hundred fifty-three thousand, twenty-one".