21004413320 has 64 divisors (see below), whose sum is σ = 53219427840. Its totient is φ = 7391577600.

The previous prime is 21004413319. The next prime is 21004413337. The reversal of 21004413320 is 2331440012.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 21004413292 and 21004413301.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 756317 + ... + 783596.

It is an arithmetic number, because the mean of its divisors is an integer number (831553560).

Almost surely, 2^21004413320 is an apocalyptic number.

21004413320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21004413320 is an abundant number, since it is smaller than the sum of its proper divisors (32215014520).

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

21004413320 is a wasteful number, since it uses less digits than its factorization.

21004413320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1539966 (or 1539962 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

Adding to 21004413320 its reverse (2331440012), we get a palindrome (23335853332).

The spelling of 21004413320 in words is "twenty-one billion, four million, four hundred thirteen thousand, three hundred twenty".