133213231 has 4 divisors (see below), whose sum is σ = 137510464. Its totient is φ = 128916000.

The previous prime is 133213229. The next prime is 133213259. The reversal of 133213231 is 132312331.

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

It is a cyclic number.

It is not a de Polignac number, because 133213231 - 2¹ = 133213229 is a prime.

It is a super-2 number, since 2×133213231² = 35491529826918722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 133213199 and 133213208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (133213271) 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, 2148570 + ... + 2148631.

It is an arithmetic number, because the mean of its divisors is an integer number (34377616).

Almost surely, 2^133213231 is an apocalyptic number.

133213231 is a deficient number, since it is larger than the sum of its proper divisors (4297233).

133213231 is an equidigital number, since it uses as much as digits as its factorization.

133213231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4297232.

The product of its digits is 324, while the sum is 19.

The square root of 133213231 is about 11541.8036285496. The cubic root of 133213231 is about 510.7195162641.

Adding to 133213231 its reverse (132312331), we get a palindrome (265525562).

The spelling of 133213231 in words is "one hundred thirty-three million, two hundred thirteen thousand, two hundred thirty-one".