181971421216792 has 8 divisors (see below), whose sum is σ = 341196414781500. Its totient is φ = 90985710608392.

The previous prime is 181971421216723. The next prime is 181971421216847. The reversal of 181971421216792 is 297612124179181.

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-2 number, since 2×181971421216792² (a number of 29 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 181971421216792.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11373213826042 + ... + 11373213826057.

Almost surely, 2^{181971421216792} is an apocalyptic number.

It is an amenable number.

181971421216792 is a deficient number, since it is larger than the sum of its proper divisors (159224993564708).

181971421216792 is a wasteful number, since it uses less digits than its factorization.

181971421216792 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22746427652105 (or 22746427652101 counting only the distinct ones).

The product of its digits is 6096384, while the sum is 61.

The spelling of 181971421216792 in words is "one hundred eighty-one trillion, nine hundred seventy-one billion, four hundred twenty-one million, two hundred sixteen thousand, seven hundred ninety-two".