21766736 has 20 divisors (see below), whose sum is σ = 43202964. Its totient is φ = 10617600.

The previous prime is 21766721. The next prime is 21766739. The reversal of 21766736 is 63766712.

It can be written as a sum of positive squares in 2 ways, for example, as 4494400 + 17272336 = 2120^2 + 4156^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21766736.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21766739) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15935 + ... + 17246.

Almost surely, 2^21766736 is an apocalyptic number.

It is an amenable number.

21766736 is a deficient number, since it is larger than the sum of its proper divisors (21436228).

21766736 is a wasteful number, since it uses less digits than its factorization.

21766736 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33230 (or 33224 counting only the distinct ones).

The product of its digits is 63504, while the sum is 38.

The square root of 21766736 is about 4665.4834690523. The cubic root of 21766736 is about 279.2100865807.

The spelling of 21766736 in words is "twenty-one million, seven hundred sixty-six thousand, seven hundred thirty-six".