21191933 has 4 divisors (see below), whose sum is σ = 24219360. Its totient is φ = 18164508.

The previous prime is 21191923. The next prime is 21191959. The reversal of 21191933 is 33919112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21191933 - 2⁴ = 21191917 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21191896 and 21191905.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21191923) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1513703 + ... + 1513716.

It is an arithmetic number, because the mean of its divisors is an integer number (6054840).

Almost surely, 2^21191933 is an apocalyptic number.

It is an amenable number.

21191933 is a deficient number, since it is larger than the sum of its proper divisors (3027427).

21191933 is an equidigital number, since it uses as much as digits as its factorization.

21191933 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3027426.

The product of its digits is 1458, while the sum is 29.

The square root of 21191933 is about 4603.4696697165. The cubic root of 21191933 is about 276.7303914436.

The spelling of 21191933 in words is "twenty-one million, one hundred ninety-one thousand, nine hundred thirty-three".