21473428 has 12 divisors (see below), whose sum is σ = 38031840. Its totient is φ = 10607192.

The previous prime is 21473423. The next prime is 21473437. The reversal of 21473428 is 82437412.

It is a super-2 number, since 2×21473428² = 922216220142368, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21473428.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21473423) 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, 32008 + ... + 32671.

It is an arithmetic number, because the mean of its divisors is an integer number (3169320).

Almost surely, 2^21473428 is an apocalyptic number.

It is an amenable number.

21473428 is a deficient number, since it is larger than the sum of its proper divisors (16558412).

21473428 is a wasteful number, since it uses less digits than its factorization.

21473428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64766 (or 64764 counting only the distinct ones).

The product of its digits is 10752, while the sum is 31.

The square root of 21473428 is about 4633.9430294297. The cubic root of 21473428 is about 277.9502869891.

The spelling of 21473428 in words is "twenty-one million, four hundred seventy-three thousand, four hundred twenty-eight".