21706036 has 24 divisors (see below), whose sum is σ = 42870240. Its totient is φ = 9525600.

The previous prime is 21706033. The next prime is 21706067. The reversal of 21706036 is 63060712.

It is a hoax number, since the sum of its digits (25) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 21706036.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21706031) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7230 + ... + 9781.

It is an arithmetic number, because the mean of its divisors is an integer number (1786260).

Almost surely, 2^21706036 is an apocalyptic number.

It is an amenable number.

21706036 is a deficient number, since it is larger than the sum of its proper divisors (21164204).

21706036 is a wasteful number, since it uses less digits than its factorization.

21706036 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17055 (or 17053 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 25.

The square root of 21706036 is about 4658.9737067298. The cubic root of 21706036 is about 278.9503043941.

Adding to 21706036 its reverse (63060712), we get a palindrome (84766748).

The spelling of 21706036 in words is "twenty-one million, seven hundred six thousand, thirty-six".