21335791 has 8 divisors (see below), whose sum is σ = 22380480. Its totient is φ = 20315808.

The previous prime is 21335779. The next prime is 21335801. The reversal of 21335791 is 19753312.

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

It is a cyclic number.

It is not a de Polignac number, because 21335791 - 2⁵ = 21335759 is a prime.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21335711) 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, 4396 + ... + 7873.

It is an arithmetic number, because the mean of its divisors is an integer number (2797560).

Almost surely, 2^21335791 is an apocalyptic number.

21335791 is a deficient number, since it is larger than the sum of its proper divisors (1044689).

21335791 is a wasteful number, since it uses less digits than its factorization.

21335791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12353.

The product of its digits is 5670, while the sum is 31.

The square root of 21335791 is about 4619.0681960759. The cubic root of 21335791 is about 277.3551596494.

The spelling of 21335791 in words is "twenty-one million, three hundred thirty-five thousand, seven hundred ninety-one".