21010933 has 4 divisors (see below), whose sum is σ = 21298828. Its totient is φ = 20723040.

The previous prime is 21010921. The next prime is 21010943. The reversal of 21010933 is 33901012.

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 6441444 + 14569489 = 2538^2 + 3817^2 .

It is a cyclic number.

It is not a de Polignac number, because 21010933 - 2²¹ = 18913781 is a prime.

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 21010933.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21010943) 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, 143838 + ... + 143983.

It is an arithmetic number, because the mean of its divisors is an integer number (5324707).

Almost surely, 2^21010933 is an apocalyptic number.

It is an amenable number.

21010933 is a deficient number, since it is larger than the sum of its proper divisors (287895).

21010933 is an equidigital number, since it uses as much as digits as its factorization.

21010933 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 287894.

The product of its (nonzero) digits is 162, while the sum is 19.

The square root of 21010933 is about 4583.7684278332. The cubic root of 21010933 is about 275.9402876143.

Adding to 21010933 its reverse (33901012), we get a palindrome (54911945).

The spelling of 21010933 in words is "twenty-one million, ten thousand, nine hundred thirty-three".