21523031442 has 48 divisors (see below), whose sum is σ = 52626862080. Its totient is φ = 6297228000.

The previous prime is 21523031423. The next prime is 21523031443. The reversal of 21523031442 is 24413032512.

21523031442 is a `hidden beast` number, since 215 + 2 + 3 + 0 + 3 + 1 + 442 = 666.

It is not an unprimeable number, because it can be changed into a prime (21523031443) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 1868434 + ... + 1879917.

It is an arithmetic number, because the mean of its divisors is an integer number (1096392960).

Almost surely, 2^21523031442 is an apocalyptic number.

21523031442 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21523031442 is an abundant number, since it is smaller than the sum of its proper divisors (31103830638).

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

21523031442 is a wasteful number, since it uses less digits than its factorization.

21523031442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3748399 (or 3748396 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 27.

Adding to 21523031442 its reverse (24413032512), we get a palindrome (45936063954).

The spelling of 21523031442 in words is "twenty-one billion, five hundred twenty-three million, thirty-one thousand, four hundred forty-two".