21795019 has 2 divisors, whose sum is σ = 21795020. Its totient is φ = 21795018.

The previous prime is 21795017. The next prime is 21795043. The reversal of 21795019 is 91059712.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21795019 - 2¹ = 21795017 is a prime.

It is a super-3 number, since 3×21795019³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

Together with 21795017, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21795017) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10897509 + 10897510.

It is an arithmetic number, because the mean of its divisors is an integer number (10897510).

Almost surely, 2^21795019 is an apocalyptic number.

21795019 is a deficient number, since it is larger than the sum of its proper divisors (1).

21795019 is an equidigital number, since it uses as much as digits as its factorization.

21795019 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5670, while the sum is 34.

The square root of 21795019 is about 4668.5135750044. The cubic root of 21795019 is about 279.3309664563.

The spelling of 21795019 in words is "twenty-one million, seven hundred ninety-five thousand, nineteen".