21051710 has 16 divisors (see below), whose sum is σ = 38515392. Its totient is φ = 8282400.

The previous prime is 21051707. The next prime is 21051721. The reversal of 21051710 is 1715012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16646 + ... + 17865.

It is an arithmetic number, because the mean of its divisors is an integer number (2407212).

Almost surely, 2^21051710 is an apocalyptic number.

21051710 is a deficient number, since it is larger than the sum of its proper divisors (17463682).

21051710 is a wasteful number, since it uses less digits than its factorization.

21051710 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34579.

The product of its (nonzero) digits is 70, while the sum is 17.

The square root of 21051710 is about 4588.2142495747. The cubic root of 21051710 is about 276.1186827673.

Adding to 21051710 its reverse (1715012), we get a palindrome (22766722).

The spelling of 21051710 in words is "twenty-one million, fifty-one thousand, seven hundred ten".