231221023 has 4 divisors (see below), whose sum is σ = 252241128. Its totient is φ = 210200920.

The previous prime is 231221009. The next prime is 231221069. The reversal of 231221023 is 320122132.

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

It is a cyclic number.

It is not a de Polignac number, because 231221023 - 2⁵ = 231220991 is a prime.

It is a super-2 number, since 2×231221023² = 106926322954333058, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 231220988 and 231221006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231221083) 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, 10510036 + ... + 10510057.

It is an arithmetic number, because the mean of its divisors is an integer number (63060282).

Almost surely, 2^231221023 is an apocalyptic number.

231221023 is a deficient number, since it is larger than the sum of its proper divisors (21020105).

231221023 is a wasteful number, since it uses less digits than its factorization.

231221023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21020104.

The product of its (nonzero) digits is 144, while the sum is 16.

The square root of 231221023 is about 15205.9535380061. The cubic root of 231221023 is about 613.7748744072.

Adding to 231221023 its reverse (320122132), we get a palindrome (551343155).

The spelling of 231221023 in words is "two hundred thirty-one million, two hundred twenty-one thousand, twenty-three".