21327636 has 24 divisors (see below), whose sum is σ = 54288864. Its totient is φ = 6462880.

The previous prime is 21327629. The next prime is 21327637. The reversal of 21327636 is 63672312.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21327637) 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, 80655 + ... + 80918.

It is an arithmetic number, because the mean of its divisors is an integer number (2262036).

Almost surely, 2^21327636 is an apocalyptic number.

It is an amenable number.

21327636 is an abundant number, since it is smaller than the sum of its proper divisors (32961228).

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

21327636 is a wasteful number, since it uses less digits than its factorization.

21327636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161591 (or 161589 counting only the distinct ones).

The product of its digits is 9072, while the sum is 30.

The square root of 21327636 is about 4618.1853579085. The cubic root of 21327636 is about 277.3198181027.

Adding to 21327636 its reverse (63672312), we get a palindrome (84999948).

It can be divided in two parts, 213276 and 36, that added together give a palindrome (213312).

The spelling of 21327636 in words is "twenty-one million, three hundred twenty-seven thousand, six hundred thirty-six".