21059417 has 2 divisors, whose sum is σ = 21059418. Its totient is φ = 21059416.

The previous prime is 21059411. The next prime is 21059449. The reversal of 21059417 is 71495012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12931216 + 8128201 = 3596^2 + 2851^2 .

It is a cyclic number.

It is not a de Polignac number, because 21059417 - 2⁸ = 21059161 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21059417.

It is not a weakly prime, because it can be changed into another prime (21059411) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10529708 + 10529709.

It is an arithmetic number, because the mean of its divisors is an integer number (10529709).

Almost surely, 2^21059417 is an apocalyptic number.

It is an amenable number.

21059417 is a deficient number, since it is larger than the sum of its proper divisors (1).

21059417 is an equidigital number, since it uses as much as digits as its factorization.

21059417 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2520, while the sum is 29.

The square root of 21059417 is about 4589.0540419568. The cubic root of 21059417 is about 276.1523742038.

The spelling of 21059417 in words is "twenty-one million, fifty-nine thousand, four hundred seventeen".