231626981 has 2 divisors, whose sum is σ = 231626982. Its totient is φ = 231626980.

The previous prime is 231626957. The next prime is 231627001. The reversal of 231626981 is 189626132.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 162154756 + 69472225 = 12734^2 + 8335^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-231626981 is a prime.

It is a super-3 number, since 3×231626981³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231626081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115813490 + 115813491.

It is an arithmetic number, because the mean of its divisors is an integer number (115813491).

Almost surely, 2^231626981 is an apocalyptic number.

It is an amenable number.

231626981 is a deficient number, since it is larger than the sum of its proper divisors (1).

231626981 is an equidigital number, since it uses as much as digits as its factorization.

231626981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 38.

The square root of 231626981 is about 15219.2963372161. The cubic root of 231626981 is about 614.1338687832.

The spelling of 231626981 in words is "two hundred thirty-one million, six hundred twenty-six thousand, nine hundred eighty-one".