20421223123 has 64 divisors (see below), whose sum is σ = 27426816000. Its totient is φ = 14779998720.

The previous prime is 20421223111. The next prime is 20421223177. The reversal of 20421223123 is 32132212402.

It is a cyclic number.

It is not a de Polignac number, because 20421223123 - 2³³ = 11831288531 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20421223094 and 20421223103.

It is not an unprimeable number, because it can be changed into a prime (20421223183) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3291178 + ... + 3297376.

It is an arithmetic number, because the mean of its divisors is an integer number (428544000).

Almost surely, 2^20421223123 is an apocalyptic number.

20421223123 is a deficient number, since it is larger than the sum of its proper divisors (7005592877).

20421223123 is a wasteful number, since it uses less digits than its factorization.

20421223123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6320.

The product of its (nonzero) digits is 1152, while the sum is 22.

Adding to 20421223123 its reverse (32132212402), we get a palindrome (52553435525).

The spelling of 20421223123 in words is "twenty billion, four hundred twenty-one million, two hundred twenty-three thousand, one hundred twenty-three".