231721603 has 2 divisors, whose sum is σ = 231721604. Its totient is φ = 231721602.

The previous prime is 231721597. The next prime is 231721631. The reversal of 231721603 is 306127132.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 231721603 - 2²⁵ = 198167171 is a prime.

It is not a weakly prime, because it can be changed into another prime (231721103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115860801 + 115860802.

It is an arithmetic number, because the mean of its divisors is an integer number (115860802).

Almost surely, 2^231721603 is an apocalyptic number.

231721603 is a deficient number, since it is larger than the sum of its proper divisors (1).

231721603 is an equidigital number, since it uses as much as digits as its factorization.

231721603 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1512, while the sum is 25.

The square root of 231721603 is about 15222.4046392152. The cubic root of 231721603 is about 614.2174840621.

Adding to 231721603 its reverse (306127132), we get a palindrome (537848735).

It can be divided in two parts, 231721 and 603, that added together give a square (232324 = 482²).

The spelling of 231721603 in words is "two hundred thirty-one million, seven hundred twenty-one thousand, six hundred three".