21210010320 has 80 divisors (see below), whose sum is σ = 65776682880. Its totient is φ = 5653796352.

The previous prime is 21210010253. The next prime is 21210010333. The reversal of 21210010320 is 2301001212.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-3 number, since 3×21210010320³ (a number of 32 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 21210010296 and 21210010305.

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, 653517 + ... + 685203.

It is an arithmetic number, because the mean of its divisors is an integer number (822208536).

Almost surely, 2^21210010320 is an apocalyptic number.

21210010320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21210010320 is an abundant number, since it is smaller than the sum of its proper divisors (44566672560).

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

21210010320 is a wasteful number, since it uses less digits than its factorization.

21210010320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34492 (or 34486 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 12.

Adding to 21210010320 its reverse (2301001212), we get a palindrome (23511011532).

The spelling of 21210010320 in words is "twenty-one billion, two hundred ten million, ten thousand, three hundred twenty".