21210734 has 16 divisors (see below), whose sum is σ = 32527440. Its totient is φ = 10370880.

The previous prime is 21210719. The next prime is 21210743. The reversal of 21210734 is 43701212.

It is a congruent number.

It is an unprimeable number.

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 in 7 ways as a sum of consecutive naturals, for example, 18572 + ... + 19680.

It is an arithmetic number, because the mean of its divisors is an integer number (2032965).

Almost surely, 2^21210734 is an apocalyptic number.

21210734 is a deficient number, since it is larger than the sum of its proper divisors (11316706).

21210734 is a wasteful number, since it uses less digits than its factorization.

21210734 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1315.

The product of its (nonzero) digits is 336, while the sum is 20.

The square root of 21210734 is about 4605.5112636927. The cubic root of 21210734 is about 276.8122035533.

Adding to 21210734 its reverse (43701212), we get a palindrome (64911946).

The spelling of 21210734 in words is "twenty-one million, two hundred ten thousand, seven hundred thirty-four".