21221022100123 has 24 divisors (see below), whose sum is σ = 21674342412800. Its totient is φ = 20776621597200.

The previous prime is 21221022100097. The next prime is 21221022100153. The reversal of 21221022100123 is 32100122012212.

It is not a de Polignac number, because 21221022100123 - 2³³ = 21212432165531 is a prime.

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 21221022100123.

It is not an unprimeable number, because it can be changed into a prime (21221022100153) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 419370778 + ... + 419421376.

Almost surely, 2^{21221022100123} is an apocalyptic number.

21221022100123 is a deficient number, since it is larger than the sum of its proper divisors (453320312677).

21221022100123 is an equidigital number, since it uses as much as digits as its factorization.

21221022100123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51319 (or 51248 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 19.

Adding to 21221022100123 its reverse (32100122012212), we get a palindrome (53321144112335).

The spelling of 21221022100123 in words is "twenty-one trillion, two hundred twenty-one billion, twenty-two million, one hundred thousand, one hundred twenty-three".