21473320 has 64 divisors (see below), whose sum is σ = 54172800. Its totient is φ = 7591680.

The previous prime is 21473293. The next prime is 21473351. The reversal of 21473320 is 2337412.

It is a super-2 number, since 2×21473320² = 922206943644800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a junction number, because it is equal to n+sod(n) for n = 21473291 and 21473300.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15621 + ... + 16939.

It is an arithmetic number, because the mean of its divisors is an integer number (846450).

Almost surely, 2^21473320 is an apocalyptic number.

21473320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21473320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27086400).

21473320 is an abundant number, since it is smaller than the sum of its proper divisors (32699480).

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

21473320 is a wasteful number, since it uses less digits than its factorization.

21473320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1378 (or 1374 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 22.

The square root of 21473320 is about 4633.9313762722. The cubic root of 21473320 is about 277.9498210072.

The spelling of 21473320 in words is "twenty-one million, four hundred seventy-three thousand, three hundred twenty".