21253531421424 has 60 divisors (see below), whose sum is σ = 58324642061624. Its totient is φ = 6667774559232.

The previous prime is 21253531421417. The next prime is 21253531421449. The reversal of 21253531421424 is 42412413535212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 766044787 + ... + 766072530.

Almost surely, 2^{21253531421424} is an apocalyptic number.

21253531421424 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21253531421424 is an abundant number, since it is smaller than the sum of its proper divisors (37071110640200).

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

21253531421424 is a wasteful number, since it uses less digits than its factorization.

21253531421424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1532117362 (or 1532117339 counting only the distinct ones).

The product of its digits is 230400, while the sum is 39.

Adding to 21253531421424 its reverse (42412413535212), we get a palindrome (63665944956636).

The spelling of 21253531421424 in words is "twenty-one trillion, two hundred fifty-three billion, five hundred thirty-one million, four hundred twenty-one thousand, four hundred twenty-four".