21000013222123 has 12 divisors (see below), whose sum is σ = 24077286308088. Its totient is φ = 18244355376000.

The previous prime is 21000013222121. The next prime is 21000013222147. The reversal of 21000013222123 is 32122231000012.

It is not a de Polignac number, because 21000013222123 - 2¹ = 21000013222121 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21000013222123.

It is not an unprimeable number, because it can be changed into a prime (21000013222121) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3654715753 + ... + 3654721498.

It is an arithmetic number, because the mean of its divisors is an integer number (2006440525674).

Almost surely, 2^{21000013222123} is an apocalyptic number.

21000013222123 is a deficient number, since it is larger than the sum of its proper divisors (3077273085965).

21000013222123 is a wasteful number, since it uses less digits than its factorization.

21000013222123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7309437294 (or 7309437281 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 21000013222123 its reverse (32122231000012), we get a palindrome (53122244222135).

The spelling of 21000013222123 in words is "twenty-one trillion, thirteen million, two hundred twenty-two thousand, one hundred twenty-three".