21003123233021 has 16 divisors (see below), whose sum is σ = 21865716848640. Its totient is φ = 20152691958960.

The previous prime is 21003123233009. The next prime is 21003123233107. The reversal of 21003123233021 is 12033232130012.

It is a cyclic number.

It is not a de Polignac number, because 21003123233021 - 2¹⁴ = 21003123216637 is a prime.

It is a super-2 number, since 2×21003123233021² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21003123233221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2842895 + ... + 7077308.

It is an arithmetic number, because the mean of its divisors is an integer number (1366607303040).

Almost surely, 2^{21003123233021} is an apocalyptic number.

It is an amenable number.

21003123233021 is a deficient number, since it is larger than the sum of its proper divisors (862593615619).

21003123233021 is a wasteful number, since it uses less digits than its factorization.

21003123233021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9920816.

The product of its (nonzero) digits is 1296, while the sum is 23.

Adding to 21003123233021 its reverse (12033232130012), we get a palindrome (33036355363033).

The spelling of 21003123233021 in words is "twenty-one trillion, three billion, one hundred twenty-three million, two hundred thirty-three thousand, twenty-one".