21233231481 has 64 divisors (see below), whose sum is σ = 38353305600. Its totient is φ = 10112558400.

The previous prime is 21233231449. The next prime is 21233231491. The reversal of 21233231481 is 18413233212.

It is not a de Polignac number, because 21233231481 - 2⁵ = 21233231449 is a prime.

It is a super-2 number, since 2×21233231481² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21233231491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 58030 + ... + 214088.

It is an arithmetic number, because the mean of its divisors is an integer number (599270400).

Almost surely, 2^21233231481 is an apocalyptic number.

21233231481 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21233231481 is a deficient number, since it is larger than the sum of its proper divisors (17120074119).

21233231481 is a wasteful number, since it uses less digits than its factorization.

21233231481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 156130.

The product of its digits is 6912, while the sum is 30.

Adding to 21233231481 its reverse (18413233212), we get a palindrome (39646464693).

The spelling of 21233231481 in words is "twenty-one billion, two hundred thirty-three million, two hundred thirty-one thousand, four hundred eighty-one".