21947033 has 4 divisors (see below), whose sum is σ = 23102160. Its totient is φ = 20791908.

The previous prime is 21947027. The next prime is 21947047. The reversal of 21947033 is 33074912.

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 21947033 - 2¹⁰ = 21946009 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21946987 and 21947005.

It is not an unprimeable number, because it can be changed into a prime (21947053) 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 3 ways as a sum of consecutive naturals, for example, 577535 + ... + 577572.

It is an arithmetic number, because the mean of its divisors is an integer number (5775540).

Almost surely, 2^21947033 is an apocalyptic number.

It is an amenable number.

21947033 is a deficient number, since it is larger than the sum of its proper divisors (1155127).

21947033 is a wasteful number, since it uses less digits than its factorization.

21947033 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1155126.

The product of its (nonzero) digits is 4536, while the sum is 29.

The square root of 21947033 is about 4684.7660560587. The cubic root of 21947033 is about 279.9788802097.

The spelling of 21947033 in words is "twenty-one million, nine hundred forty-seven thousand, thirty-three".