231281661 has 16 divisors (see below), whose sum is σ = 349576640. Its totient is φ = 134835840.

The previous prime is 231281653. The next prime is 231281693. The reversal of 231281661 is 166182132.

It is not a de Polignac number, because 231281661 - 2³ = 231281653 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231281621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 155320 + ... + 156801.

It is an arithmetic number, because the mean of its divisors is an integer number (21848540).

Almost surely, 2^231281661 is an apocalyptic number.

It is an amenable number.

231281661 is a deficient number, since it is larger than the sum of its proper divisors (118294979).

231281661 is a wasteful number, since it uses less digits than its factorization.

231281661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 312156.

The product of its digits is 3456, while the sum is 30.

The square root of 231281661 is about 15207.9472973837. The cubic root of 231281661 is about 613.8285241249.

The spelling of 231281661 in words is "two hundred thirty-one million, two hundred eighty-one thousand, six hundred sixty-one".