21310189 has 2 divisors, whose sum is σ = 21310190. Its totient is φ = 21310188.

The previous prime is 21310181. The next prime is 21310193. The reversal of 21310189 is 98101312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18275625 + 3034564 = 4275^2 + 1742^2 .

It is a cyclic number.

It is not a de Polignac number, because 21310189 - 2³ = 21310181 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21310181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10655094 + 10655095.

It is an arithmetic number, because the mean of its divisors is an integer number (10655095).

Almost surely, 2^21310189 is an apocalyptic number.

It is an amenable number.

21310189 is a deficient number, since it is larger than the sum of its proper divisors (1).

21310189 is an equidigital number, since it uses as much as digits as its factorization.

21310189 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 25.

The square root of 21310189 is about 4616.2960260365. The cubic root of 21310189 is about 277.2441772954.

The spelling of 21310189 in words is "twenty-one million, three hundred ten thousand, one hundred eighty-nine".