21291933 has 8 divisors (see below), whose sum is σ = 30573088. Its totient is φ = 13102704.

The previous prime is 21291929. The next prime is 21291937. The reversal of 21291933 is 33919212.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21291929) and next prime (21291937).

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

It is not a de Polignac number, because 21291933 - 2² = 21291929 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21291933.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21291937) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 272935 + ... + 273012.

It is an arithmetic number, because the mean of its divisors is an integer number (3821636).

Almost surely, 2^21291933 is an apocalyptic number.

It is an amenable number.

21291933 is a deficient number, since it is larger than the sum of its proper divisors (9281155).

21291933 is a wasteful number, since it uses less digits than its factorization.

21291933 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 545963.

The product of its digits is 2916, while the sum is 30.

The square root of 21291933 is about 4614.3182595049. The cubic root of 21291933 is about 277.1649848848.

The spelling of 21291933 in words is "twenty-one million, two hundred ninety-one thousand, nine hundred thirty-three".