21294617 has 2 divisors, whose sum is σ = 21294618. Its totient is φ = 21294616.

The previous prime is 21294587. The next prime is 21294629. The reversal of 21294617 is 71649212.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12645136 + 8649481 = 3556^2 + 2941^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21294617 is a prime.

It is a super-3 number, since 3×21294617³ (a number of 23 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (21294517) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10647308 + 10647309.

It is an arithmetic number, because the mean of its divisors is an integer number (10647309).

Almost surely, 2^21294617 is an apocalyptic number.

It is an amenable number.

21294617 is a deficient number, since it is larger than the sum of its proper divisors (1).

21294617 is an equidigital number, since it uses as much as digits as its factorization.

21294617 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6048, while the sum is 32.

The square root of 21294617 is about 4614.6090842020. The cubic root of 21294617 is about 277.1766306031.

The spelling of 21294617 in words is "twenty-one million, two hundred ninety-four thousand, six hundred seventeen".