21734389 has 2 divisors, whose sum is σ = 21734390. Its totient is φ = 21734388.

The previous prime is 21734357. The next prime is 21734411. The reversal of 21734389 is 98343712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16467364 + 5267025 = 4058^2 + 2295^2 .

It is a cyclic number.

It is not a de Polignac number, because 21734389 - 2⁵ = 21734357 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21734329) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10867194 + 10867195.

It is an arithmetic number, because the mean of its divisors is an integer number (10867195).

Almost surely, 2^21734389 is an apocalyptic number.

It is an amenable number.

21734389 is a deficient number, since it is larger than the sum of its proper divisors (1).

21734389 is an equidigital number, since it uses as much as digits as its factorization.

21734389 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36288, while the sum is 37.

The square root of 21734389 is about 4662.0155512396. The cubic root of 21734389 is about 279.0717089778.

The spelling of 21734389 in words is "twenty-one million, seven hundred thirty-four thousand, three hundred eighty-nine".