21487512 has 16 divisors (see below), whose sum is σ = 53718840. Its totient is φ = 7162496.

The previous prime is 21487481. The next prime is 21487519. The reversal of 21487512 is 21578412.

It is a self number, because there is not a number n which added to its sum of digits gives 21487512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21487519) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 447633 + ... + 447680.

Almost surely, 2^21487512 is an apocalyptic number.

It is an amenable number.

21487512 is an abundant number, since it is smaller than the sum of its proper divisors (32231328).

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

21487512 is a wasteful number, since it uses less digits than its factorization.

21487512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 895322 (or 895318 counting only the distinct ones).

The product of its digits is 4480, while the sum is 30.

The square root of 21487512 is about 4635.4624364782. The cubic root of 21487512 is about 278.0110410880.

The spelling of 21487512 in words is "twenty-one million, four hundred eighty-seven thousand, five hundred twelve".