133031231 has 4 divisors (see below), whose sum is σ = 133320264. Its totient is φ = 132742200.

The previous prime is 133031221. The next prime is 133031257. The reversal of 133031231 is 132130331.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-133031231 is a prime.

It is a super-2 number, since 2×133031231² = 35394616842750722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (133031221) 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, 143825 + ... + 144746.

It is an arithmetic number, because the mean of its divisors is an integer number (33330066).

Almost surely, 2^133031231 is an apocalyptic number.

133031231 is a deficient number, since it is larger than the sum of its proper divisors (289033).

133031231 is an equidigital number, since it uses as much as digits as its factorization.

133031231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 289032.

The product of its (nonzero) digits is 162, while the sum is 17.

The square root of 133031231 is about 11533.9165507645. The cubic root of 133031231 is about 510.4868233746.

Adding to 133031231 its reverse (132130331), we get a palindrome (265161562).

The spelling of 133031231 in words is "one hundred thirty-three million, thirty-one thousand, two hundred thirty-one".