21253969994224 has 160 divisors (see below), whose sum is σ = 50276949212160. Its totient is φ = 8578300723200.

The previous prime is 21253969994197. The next prime is 21253969994233. The reversal of 21253969994224 is 42249996935212.

It is a self number, because there is not a number n which added to its sum of digits gives 21253969994224.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12924697 + ... + 14476039.

It is an arithmetic number, because the mean of its divisors is an integer number (314230932576).

Almost surely, 2^{21253969994224} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21253969994224, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25138474606080).

21253969994224 is an abundant number, since it is smaller than the sum of its proper divisors (29022979217936).

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

21253969994224 is a wasteful number, since it uses less digits than its factorization.

21253969994224 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1551639 (or 1551633 counting only the distinct ones).

The product of its digits is 151165440, while the sum is 67.

The spelling of 21253969994224 in words is "twenty-one trillion, two hundred fifty-three billion, nine hundred sixty-nine million, nine hundred ninety-four thousand, two hundred twenty-four".