21331443125 has 20 divisors (see below), whose sum is σ = 26665073820. Its totient is φ = 17059200000.

The previous prime is 21331443121. The next prime is 21331443143. The reversal of 21331443125 is 52134413312.

It can be written as a sum of positive squares in 10 ways, for example, as 18932108836 + 2399334289 = 137594^2 + 48983^2 .

It is not a de Polignac number, because 21331443125 - 2² = 21331443121 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21331443121) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 2997071 + ... + 3004179.

It is an arithmetic number, because the mean of its divisors is an integer number (1333253691).

Almost surely, 2^21331443125 is an apocalyptic number.

21331443125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21331443125 is a deficient number, since it is larger than the sum of its proper divisors (5333630695).

21331443125 is an frugal number, since it uses more digits than its factorization.

21331443125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11930 (or 11915 counting only the distinct ones).

The product of its digits is 8640, while the sum is 29.

Adding to 21331443125 its reverse (52134413312), we get a palindrome (73465856437).

The spelling of 21331443125 in words is "twenty-one billion, three hundred thirty-one million, four hundred forty-three thousand, one hundred twenty-five".