21311031230320 has 160 divisors (see below), whose sum is σ = 54695060167104. Its totient is φ = 7671985152000.

The previous prime is 21311031230309. The next prime is 21311031230353. The reversal of 21311031230320 is 2303213011312.

It is a junction number, because it is equal to n+sod(n) for n = 21311031230291 and 21311031230300.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 68623395 + ... + 68933245.

Almost surely, 2^{21311031230320} is an apocalyptic number.

21311031230320 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 21311031230320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27347530083552).

21311031230320 is an abundant number, since it is smaller than the sum of its proper divisors (33384028936784).

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

21311031230320 is a wasteful number, since it uses less digits than its factorization.

21311031230320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 311531 (or 311525 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 22.

Adding to 21311031230320 its reverse (2303213011312), we get a palindrome (23614244241632).

The spelling of 21311031230320 in words is "twenty-one trillion, three hundred eleven billion, thirty-one million, two hundred thirty thousand, three hundred twenty".