21001033213021 has 8 divisors (see below), whose sum is σ = 21680493696000. Its totient is φ = 20321698217520.

The previous prime is 21001033212953. The next prime is 21001033213031. The reversal of 21001033213021 is 12031233010012.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21001033213021 is a prime.

It is a super-2 number, since 2×21001033213021² (a number of 27 digits) contains 22 as substring.

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 21001033213021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001033213031) 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, 31031686 + ... + 31701223.

It is an arithmetic number, because the mean of its divisors is an integer number (2710061712000).

Almost surely, 2^{21001033213021} is an apocalyptic number.

It is an amenable number.

21001033213021 is a deficient number, since it is larger than the sum of its proper divisors (679460482979).

21001033213021 is a wasteful number, since it uses less digits than its factorization.

21001033213021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62743739.

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 21001033213021 its reverse (12031233010012), we get a palindrome (33032266223033).

The spelling of 21001033213021 in words is "twenty-one trillion, one billion, thirty-three million, two hundred thirteen thousand, twenty-one".