123121312021 has 16 divisors (see below), whose sum is σ = 124202232000. Its totient is φ = 122046640128.

The previous prime is 123121311961. The next prime is 123121312043. The reversal of 123121312021 is 120213121321.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-123121312021 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 123121312021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123121312051) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 59106646 + ... + 59108728.

It is an arithmetic number, because the mean of its divisors is an integer number (7762639500).

Almost surely, 2^123121312021 is an apocalyptic number.

It is an amenable number.

123121312021 is a deficient number, since it is larger than the sum of its proper divisors (1080919979).

123121312021 is a wasteful number, since it uses less digits than its factorization.

123121312021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3348.

The product of its (nonzero) digits is 144, while the sum is 19.

Adding to 123121312021 its reverse (120213121321), we get a palindrome (243334433342).

The spelling of 123121312021 in words is "one hundred twenty-three billion, one hundred twenty-one million, three hundred twelve thousand, twenty-one".