231221983 has 2 divisors, whose sum is σ = 231221984. Its totient is φ = 231221982.

The previous prime is 231221957. The next prime is 231222011. The reversal of 231221983 is 389122132.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 231221983 - 2⁵ = 231221951 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231221933) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115610991 + 115610992.

It is an arithmetic number, because the mean of its divisors is an integer number (115610992).

Almost surely, 2^231221983 is an apocalyptic number.

231221983 is a deficient number, since it is larger than the sum of its proper divisors (1).

231221983 is an equidigital number, since it uses as much as digits as its factorization.

231221983 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5184, while the sum is 31.

The square root of 231221983 is about 15205.9851045567. The cubic root of 231221983 is about 613.7757238442.

The spelling of 231221983 in words is "two hundred thirty-one million, two hundred twenty-one thousand, nine hundred eighty-three".