21000012021133 has 4 divisors (see below), whose sum is σ = 21001748001820. Its totient is φ = 20998276040448.

The previous prime is 21000012021103. The next prime is 21000012021151. The reversal of 21000012021133 is 33112021000012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2313386244324 + 18686625776809 = 1520982^2 + 4322803^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21000012021133 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000012021103) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 867972198 + ... + 867996391.

It is an arithmetic number, because the mean of its divisors is an integer number (5250437000455).

Almost surely, 2^{21000012021133} is an apocalyptic number.

It is an amenable number.

21000012021133 is a deficient number, since it is larger than the sum of its proper divisors (1735980687).

21000012021133 is a wasteful number, since it uses less digits than its factorization.

21000012021133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1735980686.

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 21000012021133 its reverse (33112021000012), we get a palindrome (54112033021145).

The spelling of 21000012021133 in words is "twenty-one trillion, twelve million, twenty-one thousand, one hundred thirty-three".