21020112123 has 8 divisors (see below), whose sum is σ = 28930907136. Its totient is φ = 13561362600.

The previous prime is 21020112103. The next prime is 21020112161. The reversal of 21020112123 is 32121102012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21020112123 - 2⁶ = 21020112059 is a prime.

It is a super-2 number, since 2×21020112123² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21020112103) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 113011263 + ... + 113011448.

It is an arithmetic number, because the mean of its divisors is an integer number (3616363392).

Almost surely, 2^21020112123 is an apocalyptic number.

21020112123 is a deficient number, since it is larger than the sum of its proper divisors (7910795013).

21020112123 is a wasteful number, since it uses less digits than its factorization.

21020112123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 226022745.

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 21020112123 its reverse (32121102012), we get a palindrome (53141214135).

The spelling of 21020112123 in words is "twenty-one billion, twenty million, one hundred twelve thousand, one hundred twenty-three".