21002104320 has 160 divisors (see below), whose sum is σ = 67447683072. Its totient is φ = 5574991872.

The previous prime is 21002104313. The next prime is 21002104337. The reversal of 21002104320 is 2340120012.

It is a tau number, because it is divible by the number of its divisors (160).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21002104320.

It is a congruent number.

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, 1706509 + ... + 1718771.

Almost surely, 2^21002104320 is an apocalyptic number.

21002104320 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 21002104320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33723841536).

21002104320 is an abundant number, since it is smaller than the sum of its proper divisors (46445578752).

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

21002104320 is a wasteful number, since it uses less digits than its factorization.

21002104320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12512 (or 12496 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

Adding to 21002104320 its reverse (2340120012), we get a palindrome (23342224332).

The spelling of 21002104320 in words is "twenty-one billion, two million, one hundred four thousand, three hundred twenty".