21675889 has 2 divisors, whose sum is σ = 21675890. Its totient is φ = 21675888.

The previous prime is 21675881. The next prime is 21675893. The reversal of 21675889 is 98857612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21233664 + 442225 = 4608^2 + 665^2 .

It is a cyclic number.

It is not a de Polignac number, because 21675889 - 2³ = 21675881 is a prime.

It is not a weakly prime, because it can be changed into another prime (21675881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10837944 + 10837945.

It is an arithmetic number, because the mean of its divisors is an integer number (10837945).

Almost surely, 2^21675889 is an apocalyptic number.

It is an amenable number.

21675889 is a deficient number, since it is larger than the sum of its proper divisors (1).

21675889 is an equidigital number, since it uses as much as digits as its factorization.

21675889 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 241920, while the sum is 46.

The square root of 21675889 is about 4655.7372133745. The cubic root of 21675889 is about 278.8211020670.

The spelling of 21675889 in words is "twenty-one million, six hundred seventy-five thousand, eight hundred eighty-nine".