231021320133 has 4 divisors (see below), whose sum is σ = 308028426848. Its totient is φ = 154014213420.

The previous prime is 231021320081. The next prime is 231021320137. The reversal of 231021320133 is 331023120132.

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 not a de Polignac number, because 231021320133 - 2⁸ = 231021319877 is a prime.

It is a super-2 number, since 2×231021320133² (a number of 24 digits) 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 (231021320137) 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, 38503553353 + ... + 38503553358.

It is an arithmetic number, because the mean of its divisors is an integer number (77007106712).

Almost surely, 2^231021320133 is an apocalyptic number.

It is an amenable number.

231021320133 is a deficient number, since it is larger than the sum of its proper divisors (77007106715).

231021320133 is an equidigital number, since it uses as much as digits as its factorization.

231021320133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77007106714.

The product of its (nonzero) digits is 648, while the sum is 21.

Adding to 231021320133 its reverse (331023120132), we get a palindrome (562044440265).

The spelling of 231021320133 in words is "two hundred thirty-one billion, twenty-one million, three hundred twenty thousand, one hundred thirty-three".