21537933 has 8 divisors (see below), whose sum is σ = 28747200. Its totient is φ = 14343648.

The previous prime is 21537917. The next prime is 21537937. The reversal of 21537933 is 33973512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21537933 - 2⁴ = 21537917 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21537894 and 21537903.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21537937) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 208 + ... + 6566.

It is an arithmetic number, because the mean of its divisors is an integer number (3593400).

Almost surely, 2^21537933 is an apocalyptic number.

It is an amenable number.

21537933 is a deficient number, since it is larger than the sum of its proper divisors (7209267).

21537933 is a wasteful number, since it uses less digits than its factorization.

21537933 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7491.

The product of its digits is 17010, while the sum is 33.

The square root of 21537933 is about 4640.8978657152. The cubic root of 21537933 is about 278.2283245774.

The spelling of 21537933 in words is "twenty-one million, five hundred thirty-seven thousand, nine hundred thirty-three".