21478484 has 6 divisors (see below), whose sum is σ = 37587354. Its totient is φ = 10739240.

The previous prime is 21478453. The next prime is 21478489. The reversal of 21478484 is 48487412.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 21362884 + 115600 = 4622^2 + 340^2 .

It is a super-2 number, since 2×21478484² = 922650549876512, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21478489) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2684807 + ... + 2684814.

It is an arithmetic number, because the mean of its divisors is an integer number (6264559).

Almost surely, 2^21478484 is an apocalyptic number.

It is an amenable number.

21478484 is a deficient number, since it is larger than the sum of its proper divisors (16108870).

21478484 is a wasteful number, since it uses less digits than its factorization.

21478484 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5369625 (or 5369623 counting only the distinct ones).

The product of its digits is 57344, while the sum is 38.

The square root of 21478484 is about 4634.4885370448. The cubic root of 21478484 is about 277.9721000933.

The spelling of 21478484 in words is "twenty-one million, four hundred seventy-eight thousand, four hundred eighty-four".