231980981 has 4 divisors (see below), whose sum is σ = 232426764. Its totient is φ = 231535200.

The previous prime is 231980971. The next prime is 231980999. The reversal of 231980981 is 189089132.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 28462225 + 203518756 = 5335^2 + 14266^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-231980981 is a prime.

It is a super-2 number, since 2×231980981² = 107630351091444722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231980971) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 222110 + ... + 223151.

It is an arithmetic number, because the mean of its divisors is an integer number (58106691).

Almost surely, 2^231980981 is an apocalyptic number.

It is an amenable number.

231980981 is a deficient number, since it is larger than the sum of its proper divisors (445783).

231980981 is an equidigital number, since it uses as much as digits as its factorization.

231980981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 445782.

The product of its (nonzero) digits is 31104, while the sum is 41.

The square root of 231980981 is about 15230.9218696703. The cubic root of 231980981 is about 614.4465737606.

The spelling of 231980981 in words is "two hundred thirty-one million, nine hundred eighty thousand, nine hundred eighty-one".