231921728661 has 8 divisors (see below), whose sum is σ = 353404538944. Its totient is φ = 132526702080.

The previous prime is 231921728653. The next prime is 231921728677. The reversal of 231921728661 is 166827129132.

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

It is not a de Polignac number, because 231921728661 - 2³ = 231921728653 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 231921728661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231921728651) 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, 5521945900 + ... + 5521945941.

It is an arithmetic number, because the mean of its divisors is an integer number (44175567368).

Almost surely, 2^231921728661 is an apocalyptic number.

231921728661 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

231921728661 is a deficient number, since it is larger than the sum of its proper divisors (121482810283).

231921728661 is a wasteful number, since it uses less digits than its factorization.

231921728661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11043891851.

The product of its digits is 435456, while the sum is 48.

The spelling of 231921728661 in words is "two hundred thirty-one billion, nine hundred twenty-one million, seven hundred twenty-eight thousand, six hundred sixty-one".