20121321423 has 32 divisors (see below), whose sum is σ = 32286691840. Its totient is φ = 10888732800.

The previous prime is 20121321421. The next prime is 20121321427. The reversal of 20121321423 is 32412312102.

It is not a de Polignac number, because 20121321423 - 2¹ = 20121321421 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

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 20121321423.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20121321421) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1309461 + ... + 1324737.

It is an arithmetic number, because the mean of its divisors is an integer number (1008959120).

Almost surely, 2^20121321423 is an apocalyptic number.

20121321423 is a deficient number, since it is larger than the sum of its proper divisors (12165370417).

20121321423 is a wasteful number, since it uses less digits than its factorization.

20121321423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18607.

The product of its (nonzero) digits is 576, while the sum is 21.

Adding to 20121321423 its reverse (32412312102), we get a palindrome (52533633525).

The spelling of 20121321423 in words is "twenty billion, one hundred twenty-one million, three hundred twenty-one thousand, four hundred twenty-three".