231021133 has 16 divisors (see below), whose sum is σ = 283600000. Its totient is φ = 187590816.

The previous prime is 231021113. The next prime is 231021137. The reversal of 231021133 is 331120132.

231021133 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a de Polignac number, because none of the positive numbers 2^k-231021133 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231021137) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11208 + ... + 24241.

It is an arithmetic number, because the mean of its divisors is an integer number (17725000).

Almost surely, 2^231021133 is an apocalyptic number.

It is an amenable number.

231021133 is a deficient number, since it is larger than the sum of its proper divisors (52578867).

231021133 is an equidigital number, since it uses as much as digits as its factorization.

231021133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35489 (or 35475 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 16.

The square root of 231021133 is about 15199.3793623292. The cubic root of 231021133 is about 613.5979544637.

Adding to 231021133 its reverse (331120132), we get a palindrome (562141265).

The spelling of 231021133 in words is "two hundred thirty-one million, twenty-one thousand, one hundred thirty-three".