21251323344 has 20 divisors (see below), whose sum is σ = 54899252096. Its totient is φ = 7083774432.

The previous prime is 21251323307. The next prime is 21251323351. The reversal of 21251323344 is 44332315212.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 221367904 + ... + 221367999.

Almost surely, 2^21251323344 is an apocalyptic number.

21251323344 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21251323344 is an abundant number, since it is smaller than the sum of its proper divisors (33647928752).

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

21251323344 is a wasteful number, since it uses less digits than its factorization.

21251323344 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 442735914 (or 442735908 counting only the distinct ones).

The product of its digits is 17280, while the sum is 30.

Adding to 21251323344 its reverse (44332315212), we get a palindrome (65583638556).

The spelling of 21251323344 in words is "twenty-one billion, two hundred fifty-one million, three hundred twenty-three thousand, three hundred forty-four".