21031033320 has 256 divisors, whose sum is σ = 76772448000. Its totient is φ = 5078707200.

The previous prime is 21031033279. The next prime is 21031033321. The reversal of 21031033320 is 2333013012.

21031033320 is a `hidden beast` number, since 2 + 1 + 0 + 310 + 33 + 320 = 666.

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 = 21031033293 and 21031033302.

It is not an unprimeable number, because it can be changed into a prime (21031033321) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3192430 + ... + 3199010.

It is an arithmetic number, because the mean of its divisors is an integer number (299892375).

Almost surely, 2^21031033320 is an apocalyptic number.

21031033320 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 21031033320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38386224000).

21031033320 is an abundant number, since it is smaller than the sum of its proper divisors (55741414680).

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

21031033320 is a wasteful number, since it uses less digits than its factorization.

21031033320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6881 (or 6871 counting only the distinct ones).

The product of its (nonzero) digits is 324, while the sum is 18.

Adding to 21031033320 its reverse (2333013012), we get a palindrome (23364046332).

The spelling of 21031033320 in words is "twenty-one billion, thirty-one million, thirty-three thousand, three hundred twenty".