21636010 has 24 divisors (see below), whose sum is σ = 42809508. Its totient is φ = 7867200.

The previous prime is 21636007. The next prime is 21636023. The reversal of 21636010 is 1063612.

It can be written as a sum of positive squares in 2 ways, for example, as 21242881 + 393129 = 4609^2 + 627^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7731 + ... + 10150.

Almost surely, 2^21636010 is an apocalyptic number.

21636010 is a deficient number, since it is larger than the sum of its proper divisors (21173498).

21636010 is a wasteful number, since it uses less digits than its factorization.

21636010 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17910 (or 17899 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 19.

The square root of 21636010 is about 4651.4524613286. The cubic root of 21636010 is about 278.6500066987.

Adding to 21636010 its reverse (1063612), we get a palindrome (22699622).

The spelling of 21636010 in words is "twenty-one million, six hundred thirty-six thousand, ten".