21320212320 has 144 divisors (see below), whose sum is σ = 79369394832. Its totient is φ = 5168532480.

The previous prime is 21320212307. The next prime is 21320212327. The reversal of 21320212320 is 2321202312.

21320212320 is a `hidden beast` number, since 2 + 1 + 320 + 21 + 2 + 320 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21320212293 and 21320212302.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21320212327) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 657147 + ... + 688826.

It is an arithmetic number, because the mean of its divisors is an integer number (551176353).

Almost surely, 2^21320212320 is an apocalyptic number.

21320212320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21320212320 is an abundant number, since it is smaller than the sum of its proper divisors (58049182512).

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

21320212320 is a wasteful number, since it uses less digits than its factorization.

21320212320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1346005 (or 1345994 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

Adding to 21320212320 its reverse (2321202312), we get a palindrome (23641414632).

It can be divided in two parts, 213202 and 12320, that added together give a palindrome (225522).

The spelling of 21320212320 in words is "twenty-one billion, three hundred twenty million, two hundred twelve thousand, three hundred twenty".