21204132 has 12 divisors (see below), whose sum is σ = 49476336. Its totient is φ = 7068040.

The previous prime is 21204121. The next prime is 21204143. The reversal of 21204132 is 23140212.

It is an interprime number because it is at equal distance from previous prime (21204121) and next prime (21204143).

It is a tau number, because it is divible by the number of its divisors (12).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 883494 + ... + 883517.

It is an arithmetic number, because the mean of its divisors is an integer number (4123028).

Almost surely, 2^21204132 is an apocalyptic number.

It is an amenable number.

21204132 is an abundant number, since it is smaller than the sum of its proper divisors (28272204).

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

21204132 is a wasteful number, since it uses less digits than its factorization.

21204132 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1767018 (or 1767016 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 21204132 is about 4604.7944579536. The cubic root of 21204132 is about 276.7834806150.

Adding to 21204132 its reverse (23140212), we get a palindrome (44344344).

The spelling of 21204132 in words is "twenty-one million, two hundred four thousand, one hundred thirty-two".