21022412123 has 4 divisors (see below), whose sum is σ = 21022763088. Its totient is φ = 21022061160.

The previous prime is 21022412111. The next prime is 21022412141. The reversal of 21022412123 is 32121422012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21022412123 - 2⁴ = 21022412107 is a prime.

It is a super-2 number, since 2×21022412123² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21022412095 and 21022412104.

It is not an unprimeable number, because it can be changed into a prime (21022412023) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 60536 + ... + 213797.

It is an arithmetic number, because the mean of its divisors is an integer number (5255690772).

Almost surely, 2^21022412123 is an apocalyptic number.

21022412123 is a deficient number, since it is larger than the sum of its proper divisors (350965).

21022412123 is an equidigital number, since it uses as much as digits as its factorization.

21022412123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 350964.

The product of its (nonzero) digits is 384, while the sum is 20.

Adding to 21022412123 its reverse (32121422012), we get a palindrome (53143834135).

The spelling of 21022412123 in words is "twenty-one billion, twenty-two million, four hundred twelve thousand, one hundred twenty-three".