21947833 has 8 divisors (see below), whose sum is σ = 23806440. Its totient is φ = 20152320.

The previous prime is 21947801. The next prime is 21947837. The reversal of 21947833 is 33874912.

It can be written as a sum of positive squares in 4 ways, for example, as 1993744 + 19954089 = 1412^2 + 4467^2 .

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

It is not a de Polignac number, because 21947833 - 2⁵ = 21947801 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21947792 and 21947801.

It is not an unprimeable number, because it can be changed into a prime (21947837) 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, 15048 + ... + 16441.

It is an arithmetic number, because the mean of its divisors is an integer number (2975805).

Almost surely, 2^21947833 is an apocalyptic number.

It is an amenable number.

21947833 is a deficient number, since it is larger than the sum of its proper divisors (1858607).

21947833 is a wasteful number, since it uses less digits than its factorization.

21947833 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31547.

The product of its digits is 36288, while the sum is 37.

The square root of 21947833 is about 4684.8514384130. The cubic root of 21947833 is about 279.9822820421.

The spelling of 21947833 in words is "twenty-one million, nine hundred forty-seven thousand, eight hundred thirty-three".