21894617 has 2 divisors, whose sum is σ = 21894618. Its totient is φ = 21894616.

The previous prime is 21894599. The next prime is 21894641. The reversal of 21894617 is 71649812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20693401 + 1201216 = 4549^2 + 1096^2 .

It is a cyclic number.

It is not a de Polignac number, because 21894617 - 2¹⁸ = 21632473 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21894647) 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 as a sum of consecutive naturals, namely, 10947308 + 10947309.

It is an arithmetic number, because the mean of its divisors is an integer number (10947309).

Almost surely, 2^21894617 is an apocalyptic number.

It is an amenable number.

21894617 is a deficient number, since it is larger than the sum of its proper divisors (1).

21894617 is an equidigital number, since it uses as much as digits as its factorization.

21894617 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24192, while the sum is 38.

The square root of 21894617 is about 4679.1684090231. The cubic root of 21894617 is about 279.7558117650.

The spelling of 21894617 in words is "twenty-one million, eight hundred ninety-four thousand, six hundred seventeen".