191892071421 has 24 divisors (see below), whose sum is σ = 278779497984. Its totient is φ = 127189362240.

The previous prime is 191892071407. The next prime is 191892071447. The reversal of 191892071421 is 124170298191.

191892071421 is a `hidden beast` number, since 1 + 9 + 18 + 9 + 207 + 1 + 421 = 666.

It is not a de Polignac number, because 191892071421 - 2³⁷ = 54453117949 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (191892071621) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3248865 + ... + 3307401.

It is an arithmetic number, because the mean of its divisors is an integer number (11615812416).

Almost surely, 2^191892071421 is an apocalyptic number.

It is an amenable number.

191892071421 is a deficient number, since it is larger than the sum of its proper divisors (86887426563).

191892071421 is a wasteful number, since it uses less digits than its factorization.

191892071421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60641 (or 60638 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 45.

The spelling of 191892071421 in words is "one hundred ninety-one billion, eight hundred ninety-two million, seventy-one thousand, four hundred twenty-one".