21210033123 has 12 divisors (see below), whose sum is σ = 30682245880. Its totient is φ = 14119007616.

The previous prime is 21210033109. The next prime is 21210033139. The reversal of 21210033123 is 32133001212.

21210033123 is a `hidden beast` number, since 212 + 100 + 331 + 23 = 666.

It is not a de Polignac number, because 21210033123 - 2⁸ = 21210032867 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21210033096 and 21210033105.

It is not an unprimeable number, because it can be changed into a prime (21210033023) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1744813 + ... + 1756926.

Almost surely, 2^21210033123 is an apocalyptic number.

21210033123 is a deficient number, since it is larger than the sum of its proper divisors (9472212757).

21210033123 is a wasteful number, since it uses less digits than its factorization.

21210033123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3502418 (or 3502415 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 21210033123 its reverse (32133001212), we get a palindrome (53343034335).

The spelling of 21210033123 in words is "twenty-one billion, two hundred ten million, thirty-three thousand, one hundred twenty-three".