21310481920 has 320 divisors, whose sum is σ = 66597987456. Its totient is φ = 6346506240.

The previous prime is 21310481911. The next prime is 21310481953. The reversal of 21310481920 is 2918401312.

It is a tau number, because it is divible by the number of its divisors (320).

It is a congruent number.

It is an unprimeable number.

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 in 31 ways as a sum of consecutive naturals, for example, 3957630 + ... + 3963010.

Almost surely, 2^21310481920 is an apocalyptic number.

21310481920 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 21310481920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33298993728).

21310481920 is an abundant number, since it is smaller than the sum of its proper divisors (45287505536).

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

21310481920 is a wasteful number, since it uses less digits than its factorization.

21310481920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5441 (or 5425 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 31.

The spelling of 21310481920 in words is "twenty-one billion, three hundred ten million, four hundred eighty-one thousand, nine hundred twenty".