191421131121 has 40 divisors (see below), whose sum is σ = 312028051104. Its totient is φ = 115982124480.

The previous prime is 191421131051. The next prime is 191421131149. The reversal of 191421131121 is 121131124191.

191421131121 is a `hidden beast` number, since 1 + 91 + 421 + 1 + 31 + 121 = 666.

It is not a de Polignac number, because 191421131121 - 2⁹ = 191421130609 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (191421131921) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 3602670 + ... + 3655416.

Almost surely, 2^191421131121 is an apocalyptic number.

191421131121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

191421131121 is a deficient number, since it is larger than the sum of its proper divisors (120606919983).

191421131121 is a wasteful number, since it uses less digits than its factorization.

191421131121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56843 (or 56834 counting only the distinct ones).

The product of its digits is 432, while the sum is 27.

The spelling of 191421131121 in words is "one hundred ninety-one billion, four hundred twenty-one million, one hundred thirty-one thousand, one hundred twenty-one".