21310133 has 4 divisors (see below), whose sum is σ = 22949388. Its totient is φ = 19670880.

The previous prime is 21310117. The next prime is 21310139. The reversal of 21310133 is 33101312.

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 14303524 + 7006609 = 3782^2 + 2647^2 .

It is a cyclic number.

It is not a de Polignac number, because 21310133 - 2⁴ = 21310117 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 (21310139) 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, 819608 + ... + 819633.

It is an arithmetic number, because the mean of its divisors is an integer number (5737347).

Almost surely, 2^21310133 is an apocalyptic number.

It is an amenable number.

21310133 is a deficient number, since it is larger than the sum of its proper divisors (1639255).

21310133 is a wasteful number, since it uses less digits than its factorization.

21310133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1639254.

The product of its (nonzero) digits is 54, while the sum is 14.

The square root of 21310133 is about 4616.2899605636. The cubic root of 21310133 is about 277.2439344431.

Adding to 21310133 its reverse (33101312), we get a palindrome (54411445).

The spelling of 21310133 in words is "twenty-one million, three hundred ten thousand, one hundred thirty-three".