231402209 has 2 divisors, whose sum is σ = 231402210. Its totient is φ = 231402208.

The previous prime is 231402173. The next prime is 231402217. The reversal of 231402209 is 902204132.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 179158225 + 52243984 = 13385^2 + 7228^2 .

It is a cyclic number.

It is not a de Polignac number, because 231402209 - 2¹² = 231398113 is a prime.

It is not a weakly prime, because it can be changed into another prime (231402299) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115701104 + 115701105.

It is an arithmetic number, because the mean of its divisors is an integer number (115701105).

Almost surely, 2^231402209 is an apocalyptic number.

It is an amenable number.

231402209 is a deficient number, since it is larger than the sum of its proper divisors (1).

231402209 is an equidigital number, since it uses as much as digits as its factorization.

231402209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 231402209 is about 15211.9101035997. The cubic root of 231402209 is about 613.9351516144.

The spelling of 231402209 in words is "two hundred thirty-one million, four hundred two thousand, two hundred nine".