21340889 has 2 divisors, whose sum is σ = 21340890. Its totient is φ = 21340888.

The previous prime is 21340883. The next prime is 21340931. The reversal of 21340889 is 98804312.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13017664 + 8323225 = 3608^2 + 2885^2 .

It is a cyclic number.

It is not a de Polignac number, because 21340889 - 2⁸ = 21340633 is a prime.

It is not a weakly prime, because it can be changed into another prime (21340883) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10670444 + 10670445.

It is an arithmetic number, because the mean of its divisors is an integer number (10670445).

Almost surely, 2^21340889 is an apocalyptic number.

It is an amenable number.

21340889 is a deficient number, since it is larger than the sum of its proper divisors (1).

21340889 is an equidigital number, since it uses as much as digits as its factorization.

21340889 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13824, while the sum is 35.

The square root of 21340889 is about 4619.6200060178. The cubic root of 21340889 is about 277.3772484172.

The spelling of 21340889 in words is "twenty-one million, three hundred forty thousand, eight hundred eighty-nine".