21231145320 has 192 divisors, whose sum is σ = 80828280000. Its totient is φ = 4411653120.

The previous prime is 21231145303. The next prime is 21231145349. The reversal of 21231145320 is 2354113212.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 99445 + ... + 228804.

It is an arithmetic number, because the mean of its divisors is an integer number (420980625).

Almost surely, 2^21231145320 is an apocalyptic number.

21231145320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21231145320 is an abundant number, since it is smaller than the sum of its proper divisors (59597134680).

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

21231145320 is a wasteful number, since it uses less digits than its factorization.

21231145320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 328288 (or 328277 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 24.

Adding to 21231145320 its reverse (2354113212), we get a palindrome (23585258532).

The spelling of 21231145320 in words is "twenty-one billion, two hundred thirty-one million, one hundred forty-five thousand, three hundred twenty".