21147132 has 12 divisors (see below), whose sum is σ = 49343336. Its totient is φ = 7049040.

The previous prime is 21147127. The next prime is 21147157. The reversal of 21147132 is 23174112.

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

It is a junction number, because it is equal to n+sod(n) for n = 21147099 and 21147108.

It is a congruent number.

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, 881119 + ... + 881142.

Almost surely, 2^21147132 is an apocalyptic number.

It is an amenable number.

21147132 is an abundant number, since it is smaller than the sum of its proper divisors (28196204).

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

21147132 is a wasteful number, since it uses less digits than its factorization.

21147132 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1762268 (or 1762266 counting only the distinct ones).

The product of its digits is 336, while the sum is 21.

The square root of 21147132 is about 4598.6010916365. The cubic root of 21147132 is about 276.5352457231.

It can be divided in two parts, 21 and 147132, that added together give a triangular number (147153 = T₅₄₂).

The spelling of 21147132 in words is "twenty-one million, one hundred forty-seven thousand, one hundred thirty-two".