21323310320 has 80 divisors (see below), whose sum is σ = 55112639232. Its totient is φ = 7619235840.

The previous prime is 21323310313. The next prime is 21323310343. The reversal of 21323310320 is 2301332312.

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

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 = 21323310292 and 21323310301.

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, 298457 + ... + 362936.

Almost surely, 2^21323310320 is an apocalyptic number.

21323310320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21323310320 is an abundant number, since it is smaller than the sum of its proper divisors (33789328912).

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

21323310320 is a wasteful number, since it uses less digits than its factorization.

21323310320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 661450 (or 661444 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 20.

Adding to 21323310320 its reverse (2301332312), we get a palindrome (23624642632).

The spelling of 21323310320 in words is "twenty-one billion, three hundred twenty-three million, three hundred ten thousand, three hundred twenty".