21470784 has 28 divisors (see below), whose sum is σ = 56808624. Its totient is φ = 7156864.

The previous prime is 21470783. The next prime is 21470807. The reversal of 21470784 is 48707412.

It is not an unprimeable number, because it can be changed into a prime (21470783) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 55722 + ... + 56105.

Almost surely, 2^21470784 is an apocalyptic number.

21470784 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21470784 is an abundant number, since it is smaller than the sum of its proper divisors (35337840).

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

21470784 is a wasteful number, since it uses less digits than its factorization.

21470784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111842 (or 111832 counting only the distinct ones).

The product of its (nonzero) digits is 12544, while the sum is 33.

The square root of 21470784 is about 4633.6577344469. The cubic root of 21470784 is about 277.9388786146.

The spelling of 21470784 in words is "twenty-one million, four hundred seventy thousand, seven hundred eighty-four".