231635721161 has 12 divisors (see below), whose sum is σ = 251949293568. Its totient is φ = 212858730864.

The previous prime is 231635721139. The next prime is 231635721173. The reversal of 231635721161 is 161127536132.

It is a happy number.

It is not a de Polignac number, because 231635721161 - 2³⁰ = 230561979337 is a prime.

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (231635721461) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3035465 + ... + 3110838.

It is an arithmetic number, because the mean of its divisors is an integer number (20995774464).

Almost surely, 2^231635721161 is an apocalyptic number.

It is an amenable number.

231635721161 is a deficient number, since it is larger than the sum of its proper divisors (20313572407).

231635721161 is a wasteful number, since it uses less digits than its factorization.

231635721161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6146552 (or 6146539 counting only the distinct ones).

The product of its digits is 45360, while the sum is 38.

The spelling of 231635721161 in words is "two hundred thirty-one billion, six hundred thirty-five million, seven hundred twenty-one thousand, one hundred sixty-one".