20121313123 has 4 divisors (see below), whose sum is σ = 20996152848. Its totient is φ = 19246473400.

The previous prime is 20121313109. The next prime is 20121313133. The reversal of 20121313123 is 32131312102.

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 20121313123 - 2²¹ = 20119215971 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20121313123.

It is not an unprimeable number, because it can be changed into a prime (20121313133) 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, 437419828 + ... + 437419873.

It is an arithmetic number, because the mean of its divisors is an integer number (5249038212).

Almost surely, 2^20121313123 is an apocalyptic number.

20121313123 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

20121313123 is a deficient number, since it is larger than the sum of its proper divisors (874839725).

20121313123 is an equidigital number, since it uses as much as digits as its factorization.

20121313123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 874839724.

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 20121313123 its reverse (32131312102), we get a palindrome (52252625225).

The spelling of 20121313123 in words is "twenty billion, one hundred twenty-one million, three hundred thirteen thousand, one hundred twenty-three".