21253223531456 has 168 divisors, whose sum is σ = 49380356093040. Its totient is φ = 9049121292288.

The previous prime is 21253223531453. The next prime is 21253223531461. The reversal of 21253223531456 is 65413532235212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21253223531453) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 764408051 + ... + 764435853.

It is an arithmetic number, because the mean of its divisors is an integer number (293930691030).

Almost surely, 2^{21253223531456} 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 21253223531456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24690178046520).

21253223531456 is an abundant number, since it is smaller than the sum of its proper divisors (28127132561584).

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

21253223531456 is a wasteful number, since it uses less digits than its factorization.

21253223531456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29411 (or 29394 counting only the distinct ones).

The product of its digits is 1296000, while the sum is 44.

Adding to 21253223531456 its reverse (65413532235212), we get a palindrome (86666755766668).

The spelling of 21253223531456 in words is "twenty-one trillion, two hundred fifty-three billion, two hundred twenty-three million, five hundred thirty-one thousand, four hundred fifty-six".