21002110123 has 8 divisors (see below), whose sum is σ = 22130701200. Its totient is φ = 19875840768.

The previous prime is 21002110069. The next prime is 21002110139. The reversal of 21002110123 is 32101120012.

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

It is a cyclic number.

It is not a de Polignac number, because 21002110123 - 2¹³ = 21002101931 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21002110183) 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, 561838 + ... + 598051.

It is an arithmetic number, because the mean of its divisors is an integer number (2766337650).

Almost surely, 2^21002110123 is an apocalyptic number.

21002110123 is a deficient number, since it is larger than the sum of its proper divisors (1128591077).

21002110123 is a wasteful number, since it uses less digits than its factorization.

21002110123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1160861.

The product of its (nonzero) digits is 24, while the sum is 13.

Adding to 21002110123 its reverse (32101120012), we get a palindrome (53103230135).

The spelling of 21002110123 in words is "twenty-one billion, two million, one hundred ten thousand, one hundred twenty-three".