191531133021 has 8 divisors (see below), whose sum is σ = 255462402784. Its totient is φ = 127643642640.

The previous prime is 191531132999. The next prime is 191531133047. The reversal of 191531133021 is 120331135191.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 191531133021 - 2²¹ = 191529035869 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 191531133021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (191531133121) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10934635 + ... + 10952136.

It is an arithmetic number, because the mean of its divisors is an integer number (31932800348).

Almost surely, 2^191531133021 is an apocalyptic number.

It is an amenable number.

191531133021 is a deficient number, since it is larger than the sum of its proper divisors (63931269763).

191531133021 is a wasteful number, since it uses less digits than its factorization.

191531133021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21889691.

The product of its (nonzero) digits is 2430, while the sum is 30.

The spelling of 191531133021 in words is "one hundred ninety-one billion, five hundred thirty-one million, one hundred thirty-three thousand, twenty-one".