21036707 has 4 divisors (see below), whose sum is σ = 21433680. Its totient is φ = 20639736.

The previous prime is 21036689. The next prime is 21036709. The reversal of 21036707 is 70763012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21036707 - 2⁸ = 21036451 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21036709) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 198407 + ... + 198512.

It is an arithmetic number, because the mean of its divisors is an integer number (5358420).

Almost surely, 2^21036707 is an apocalyptic number.

21036707 is a deficient number, since it is larger than the sum of its proper divisors (396973).

21036707 is an equidigital number, since it uses as much as digits as its factorization.

21036707 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 396972.

The product of its (nonzero) digits is 1764, while the sum is 26.

The square root of 21036707 is about 4586.5790083678. The cubic root of 21036707 is about 276.0530730046.

Adding to 21036707 its reverse (70763012), we get a palindrome (91799719).

The spelling of 21036707 in words is "twenty-one million, thirty-six thousand, seven hundred seven".