131220123 has 4 divisors (see below), whose sum is σ = 174960168. Its totient is φ = 87480080.

The previous prime is 131220101. The next prime is 131220143. The reversal of 131220123 is 321022131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 321022131 = 3 ⋅107007377.

It is a cyclic number.

It is not a de Polignac number, because 131220123 - 2¹⁸ = 130957979 is a prime.

It is not an unprimeable number, because it can be changed into a prime (131220143) 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, 21870018 + ... + 21870023.

It is an arithmetic number, because the mean of its divisors is an integer number (43740042).

Almost surely, 2^131220123 is an apocalyptic number.

131220123 is a deficient number, since it is larger than the sum of its proper divisors (43740045).

131220123 is an equidigital number, since it uses as much as digits as its factorization.

131220123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43740044.

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 131220123 is about 11455.1352239945. The cubic root of 131220123 is about 508.1596143713.

Adding to 131220123 its reverse (321022131), we get a palindrome (452242254).

The spelling of 131220123 in words is "one hundred thirty-one million, two hundred twenty thousand, one hundred twenty-three".