21094417 has 2 divisors, whose sum is σ = 21094418. Its totient is φ = 21094416.

The previous prime is 21094393. The next prime is 21094421. The reversal of 21094417 is 71449012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13608721 + 7485696 = 3689^2 + 2736^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21094417 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21094457) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10547208 + 10547209.

It is an arithmetic number, because the mean of its divisors is an integer number (10547209).

Almost surely, 2^21094417 is an apocalyptic number.

It is an amenable number.

21094417 is a deficient number, since it is larger than the sum of its proper divisors (1).

21094417 is an equidigital number, since it uses as much as digits as its factorization.

21094417 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 21094417 is about 4592.8658809070. The cubic root of 21094417 is about 276.3052746625.

The spelling of 21094417 in words is "twenty-one million, ninety-four thousand, four hundred seventeen".