21027312 has 30 divisors (see below), whose sum is σ = 58847672. Its totient is φ = 7009056.

The previous prime is 21027287. The next prime is 21027323. The reversal of 21027312 is 21372012.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

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 5 ways as a sum of consecutive naturals, for example, 72868 + ... + 73155.

Almost surely, 2^21027312 is an apocalyptic number.

It is an amenable number.

21027312 is an abundant number, since it is smaller than the sum of its proper divisors (37820360).

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

21027312 is a wasteful number, since it uses less digits than its factorization.

21027312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146037 (or 146028 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 18.

The square root of 21027312 is about 4585.5547101741. The cubic root of 21027312 is about 276.0119717554.

Adding to 21027312 its reverse (21372012), we get a palindrome (42399324).

The spelling of 21027312 in words is "twenty-one million, twenty-seven thousand, three hundred twelve".