21307834 has 8 divisors (see below), whose sum is σ = 33841908. Its totient is φ = 10027200.

The previous prime is 21307829. The next prime is 21307841. The reversal of 21307834 is 43870312.

It can be written as a sum of positive squares in 2 ways, for example, as 16834609 + 4473225 = 4103^2 + 2115^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

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, 313317 + ... + 313384.

Almost surely, 2^21307834 is an apocalyptic number.

21307834 is a deficient number, since it is larger than the sum of its proper divisors (12534074).

21307834 is a wasteful number, since it uses less digits than its factorization.

21307834 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 626720.

The product of its (nonzero) digits is 4032, while the sum is 28.

The square root of 21307834 is about 4616.0409443591. The cubic root of 21307834 is about 277.2339641201.

The spelling of 21307834 in words is "twenty-one million, three hundred seven thousand, eight hundred thirty-four".