21034289 has 4 divisors (see below), whose sum is σ = 21043824. Its totient is φ = 21024756.

The previous prime is 21034261. The next prime is 21034297. The reversal of 21034289 is 98243012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21034289 - 2⁸ = 21034033 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21034229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 434 + ... + 6500.

It is an arithmetic number, because the mean of its divisors is an integer number (5260956).

Almost surely, 2^21034289 is an apocalyptic number.

It is an amenable number.

21034289 is a deficient number, since it is larger than the sum of its proper divisors (9535).

21034289 is an equidigital number, since it uses as much as digits as its factorization.

21034289 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9534.

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 21034289 is about 4586.3154056388. The cubic root of 21034289 is about 276.0424959070.

The spelling of 21034289 in words is "twenty-one million, thirty-four thousand, two hundred eighty-nine".