231639401 has 4 divisors (see below), whose sum is σ = 264730752. Its totient is φ = 198548052.

The previous prime is 231639391. The next prime is 231639413. The reversal of 231639401 is 104936132.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 231639401 - 2⁶ = 231639337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (231639451) 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, 16545665 + ... + 16545678.

It is an arithmetic number, because the mean of its divisors is an integer number (66182688).

Almost surely, 2^231639401 is an apocalyptic number.

It is an amenable number.

231639401 is a deficient number, since it is larger than the sum of its proper divisors (33091351).

231639401 is an equidigital number, since it uses as much as digits as its factorization.

231639401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33091350.

The product of its (nonzero) digits is 3888, while the sum is 29.

The square root of 231639401 is about 15219.7043663798. The cubic root of 231639401 is about 614.1448453489.

The spelling of 231639401 in words is "two hundred thirty-one million, six hundred thirty-nine thousand, four hundred one".