21519533 has 16 divisors (see below), whose sum is σ = 26593920. Its totient is φ = 16998336.

The previous prime is 21519523. The next prime is 21519539. The reversal of 21519533 is 33591512.

It is a cyclic number.

It is not a de Polignac number, because 21519533 - 2⁴ = 21519517 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21519496 and 21519505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21519539) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2735 + ... + 7107.

It is an arithmetic number, because the mean of its divisors is an integer number (1662120).

Almost surely, 2^21519533 is an apocalyptic number.

It is an amenable number.

21519533 is a deficient number, since it is larger than the sum of its proper divisors (5074387).

21519533 is a wasteful number, since it uses less digits than its factorization.

21519533 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4436.

The product of its digits is 4050, while the sum is 29.

The square root of 21519533 is about 4638.9150671251. The cubic root of 21519533 is about 278.1490712323.

The spelling of 21519533 in words is "twenty-one million, five hundred nineteen thousand, five hundred thirty-three".