21533444442 has 24 divisors (see below), whose sum is σ = 47793744180. Its totient is φ = 7002745920.

The previous prime is 21533444419. The next prime is 21533444467. The reversal of 21533444442 is 24444433512.

21533444442 is a `hidden beast` number, since 2 + 1 + 533 + 44 + 44 + 42 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 16962197121 + 4571247321 = 130239^2 + 67611^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21533444397 and 21533444406.

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 11 ways as a sum of consecutive naturals, for example, 14588317 + ... + 14589792.

Almost surely, 2^21533444442 is an apocalyptic number.

21533444442 is an abundant number, since it is smaller than the sum of its proper divisors (26260299738).

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

21533444442 is a wasteful number, since it uses less digits than its factorization.

21533444442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29178158 (or 29178155 counting only the distinct ones).

The product of its digits is 184320, while the sum is 36.

Adding to 21533444442 its reverse (24444433512), we get a palindrome (45977877954).

The spelling of 21533444442 in words is "twenty-one billion, five hundred thirty-three million, four hundred forty-four thousand, four hundred forty-two".