21231033320 has 32 divisors (see below), whose sum is σ = 54594086400. Its totient is φ = 7279211328.

The previous prime is 21231033319. The next prime is 21231033331. The reversal of 21231033320 is 2333013212.

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 = 21231033292 and 21231033301.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 37912280 + ... + 37912839.

It is an arithmetic number, because the mean of its divisors is an integer number (1706065200).

Almost surely, 2^21231033320 is an apocalyptic number.

21231033320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21231033320 is an abundant number, since it is smaller than the sum of its proper divisors (33363053080).

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

21231033320 is a wasteful number, since it uses less digits than its factorization.

21231033320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75825137 (or 75825133 counting only the distinct ones).

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

Adding to 21231033320 its reverse (2333013212), we get a palindrome (23564046532).

The spelling of 21231033320 in words is "twenty-one billion, two hundred thirty-one million, thirty-three thousand, three hundred twenty".