21794473 has 2 divisors, whose sum is σ = 21794474. Its totient is φ = 21794472.

The previous prime is 21794471. The next prime is 21794489. The reversal of 21794473 is 37449712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15904144 + 5890329 = 3988^2 + 2427^2 .

It is a cyclic number.

It is not a de Polignac number, because 21794473 - 2¹ = 21794471 is a prime.

Together with 21794471, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21794471) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10897236 + 10897237.

It is an arithmetic number, because the mean of its divisors is an integer number (10897237).

Almost surely, 2^21794473 is an apocalyptic number.

It is an amenable number.

21794473 is a deficient number, since it is larger than the sum of its proper divisors (1).

21794473 is an equidigital number, since it uses as much as digits as its factorization.

21794473 is an evil number, because the sum of its binary digits is even.

The product of its digits is 42336, while the sum is 37.

The square root of 21794473 is about 4668.4550977813. The cubic root of 21794473 is about 279.3286338747.

The spelling of 21794473 in words is "twenty-one million, seven hundred ninety-four thousand, four hundred seventy-three".