21540933 has 12 divisors (see below), whose sum is σ = 31165888. Its totient is φ = 14337000.

The previous prime is 21540917. The next prime is 21540947. The reversal of 21540933 is 33904512.

It is not a de Polignac number, because 21540933 - 2⁴ = 21540917 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21540897 and 21540906.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21540983) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5166 + ... + 8352.

Almost surely, 2^21540933 is an apocalyptic number.

It is an amenable number.

21540933 is a deficient number, since it is larger than the sum of its proper divisors (9624955).

21540933 is a wasteful number, since it uses less digits than its factorization.

21540933 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3944 (or 3941 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 27.

The square root of 21540933 is about 4641.2210677795. The cubic root of 21540933 is about 278.2412420383.

The spelling of 21540933 in words is "twenty-one million, five hundred forty thousand, nine hundred thirty-three".