21003110021 has 8 divisors (see below), whose sum is σ = 21377541888. Its totient is φ = 20630862000.

The previous prime is 21003109997. The next prime is 21003110027. The reversal of 21003110021 is 12001130012.

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 21003110021 - 2¹⁴ = 21003093637 is a prime.

It is a super-2 number, since 2×21003110021² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21003109984 and 21003110011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21003110027) 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, 526550 + ... + 565031.

It is an arithmetic number, because the mean of its divisors is an integer number (2672192736).

Almost surely, 2^21003110021 is an apocalyptic number.

It is an amenable number.

21003110021 is a deficient number, since it is larger than the sum of its proper divisors (374431867).

21003110021 is a wasteful number, since it uses less digits than its factorization.

21003110021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1091923.

The product of its (nonzero) digits is 12, while the sum is 11.

Adding to 21003110021 its reverse (12001130012), we get a palindrome (33004240033).

The spelling of 21003110021 in words is "twenty-one billion, three million, one hundred ten thousand, twenty-one".