21135706 has 16 divisors (see below), whose sum is σ = 32332608. Its totient is φ = 10360000.

The previous prime is 21135691. The next prime is 21135713. The reversal of 21135706 is 60753112.

It is a zygodrome in base 4.

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, 35346 + ... + 35938.

It is an arithmetic number, because the mean of its divisors is an integer number (2020788).

Almost surely, 2^21135706 is an apocalyptic number.

21135706 is a deficient number, since it is larger than the sum of its proper divisors (11196902).

21135706 is a wasteful number, since it uses less digits than its factorization.

21135706 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 917.

The product of its (nonzero) digits is 1260, while the sum is 25.

The square root of 21135706 is about 4597.3585894511. The cubic root of 21135706 is about 276.4854318609.

Adding to 21135706 its reverse (60753112), we get a palindrome (81888818).

The spelling of 21135706 in words is "twenty-one million, one hundred thirty-five thousand, seven hundred six".