2131220123 has 4 divisors (see below), whose sum is σ = 2176565280. Its totient is φ = 2085874968.

The previous prime is 2131220083. The next prime is 2131220131. The reversal of 2131220123 is 3210221312.

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 2131220123 - 2¹⁰ = 2131219099 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2131220323) 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, 22672508 + ... + 22672601.

It is an arithmetic number, because the mean of its divisors is an integer number (544141320).

Almost surely, 2^2131220123 is an apocalyptic number.

2131220123 is a deficient number, since it is larger than the sum of its proper divisors (45345157).

2131220123 is an equidigital number, since it uses as much as digits as its factorization.

2131220123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45345156.

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 2131220123 is about 46165.1396943625. The cubic root of 2131220123 is about 1286.8939802670.

Adding to 2131220123 its reverse (3210221312), we get a palindrome (5341441435).

The spelling of 2131220123 in words is "two billion, one hundred thirty-one million, two hundred twenty thousand, one hundred twenty-three".