21060636 has 24 divisors (see below), whose sum is σ = 49339920. Its totient is φ = 6991872.

The previous prime is 21060631. The next prime is 21060643. The reversal of 21060636 is 63606012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21060631) 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, 331 + ... + 6498.

It is an arithmetic number, because the mean of its divisors is an integer number (2055830).

Almost surely, 2^21060636 is an apocalyptic number.

It is an amenable number.

21060636 is an abundant number, since it is smaller than the sum of its proper divisors (28279284).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21060636 is a wasteful number, since it uses less digits than its factorization.

21060636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7093 (or 7091 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 24.

The square root of 21060636 is about 4589.1868560781. The cubic root of 21060636 is about 276.1577023546.

Adding to 21060636 its reverse (63606012), we get a palindrome (84666648).

The spelling of 21060636 in words is "twenty-one million, sixty thousand, six hundred thirty-six".