21036715 has 16 divisors (see below), whose sum is σ = 28926720. Its totient is φ = 14387040.

The previous prime is 21036713. The next prime is 21036721. The reversal of 21036715 is 51763012.

It is not a de Polignac number, because 21036715 - 2¹ = 21036713 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21036715.

It is not an unprimeable number, because it can be changed into a prime (21036713) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21180 + ... + 22150.

It is an arithmetic number, because the mean of its divisors is an integer number (1807920).

Almost surely, 2^21036715 is an apocalyptic number.

21036715 is a deficient number, since it is larger than the sum of its proper divisors (7890005).

21036715 is an equidigital number, since it uses as much as digits as its factorization.

21036715 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1602.

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

The square root of 21036715 is about 4586.5798804774. The cubic root of 21036715 is about 276.0531079977.

Adding to 21036715 its reverse (51763012), we get a palindrome (72799727).

The spelling of 21036715 in words is "twenty-one million, thirty-six thousand, seven hundred fifteen".