21127636 has 12 divisors (see below), whose sum is σ = 37026612. Its totient is φ = 10548608.

The previous prime is 21127633. The next prime is 21127637. The reversal of 21127636 is 63672112.

It can be written as a sum of positive squares in 2 ways, for example, as 1943236 + 19184400 = 1394^2 + 4380^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21127633) 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, 325 + ... + 6508.

It is an arithmetic number, because the mean of its divisors is an integer number (3085551).

Almost surely, 2^21127636 is an apocalyptic number.

It is an amenable number.

21127636 is a deficient number, since it is larger than the sum of its proper divisors (15898976).

21127636 is a wasteful number, since it uses less digits than its factorization.

21127636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7610 (or 7608 counting only the distinct ones).

The product of its digits is 3024, while the sum is 28.

The square root of 21127636 is about 4596.4808277638. The cubic root of 21127636 is about 276.4502383126.

Adding to 21127636 its reverse (63672112), we get a palindrome (84799748).

The spelling of 21127636 in words is "twenty-one million, one hundred twenty-seven thousand, six hundred thirty-six".