21384512 has 14 divisors (see below), whose sum is σ = 42435018. Its totient is φ = 10692224.

The previous prime is 21384511. The next prime is 21384529. The reversal of 21384512 is 21548312.

It can be written as a sum of positive squares in only one way, i.e., 21381376 + 3136 = 4624^2 + 56^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21384511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 167003 + ... + 167130.

Almost surely, 2^21384512 is an apocalyptic number.

It is an amenable number.

21384512 is a deficient number, since it is larger than the sum of its proper divisors (21050506).

21384512 is an equidigital number, since it uses as much as digits as its factorization.

21384512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 334145 (or 334135 counting only the distinct ones).

The product of its digits is 1920, while the sum is 26.

The square root of 21384512 is about 4624.3390879130. The cubic root of 21384512 is about 277.5661157833.

The spelling of 21384512 in words is "twenty-one million, three hundred eighty-four thousand, five hundred twelve".