21466859 has 2 divisors, whose sum is σ = 21466860. Its totient is φ = 21466858.

The previous prime is 21466831. The next prime is 21466883. The reversal of 21466859 is 95866412.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21466859 - 2¹⁶ = 21401323 is a prime.

It is a super-3 number, since 3×21466859³ (a number of 23 digits) contains 333 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21466829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10733429 + 10733430.

It is an arithmetic number, because the mean of its divisors is an integer number (10733430).

Almost surely, 2^21466859 is an apocalyptic number.

21466859 is a deficient number, since it is larger than the sum of its proper divisors (1).

21466859 is an equidigital number, since it uses as much as digits as its factorization.

21466859 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 103680, while the sum is 41.

The square root of 21466859 is about 4633.2341835914. The cubic root of 21466859 is about 277.9219412331.

The spelling of 21466859 in words is "twenty-one million, four hundred sixty-six thousand, eight hundred fifty-nine".