231221827 has 2 divisors, whose sum is σ = 231221828. Its totient is φ = 231221826.

The previous prime is 231221801. The next prime is 231221831. The reversal of 231221827 is 728122132.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 231221827 - 2¹⁵ = 231189059 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 231221795 and 231221804.

It is not a weakly prime, because it can be changed into another prime (231221867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115610913 + 115610914.

It is an arithmetic number, because the mean of its divisors is an integer number (115610914).

Almost surely, 2^231221827 is an apocalyptic number.

231221827 is a deficient number, since it is larger than the sum of its proper divisors (1).

231221827 is an equidigital number, since it uses as much as digits as its factorization.

231221827 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2688, while the sum is 28.

The square root of 231221827 is about 15205.9799749967. The cubic root of 231221827 is about 613.7755858108.

Adding to 231221827 its reverse (728122132), we get a palindrome (959343959).

The spelling of 231221827 in words is "two hundred thirty-one million, two hundred twenty-one thousand, eight hundred twenty-seven".