21232275456 has 312 divisors, whose sum is σ = 66559410720. Its totient is φ = 6001852416.

The previous prime is 21232275451. The next prime is 21232275469. The reversal of 21232275456 is 65457223212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21232275451) 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, 107777950 + ... + 107778146.

Almost surely, 2^21232275456 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 21232275456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33279705360).

21232275456 is an abundant number, since it is smaller than the sum of its proper divisors (45327135264).

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

21232275456 is a wasteful number, since it uses less digits than its factorization.

21232275456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 417 (or 388 counting only the distinct ones).

The product of its digits is 201600, while the sum is 39.

Adding to 21232275456 its reverse (65457223212), we get a palindrome (86689498668).

The spelling of 21232275456 in words is "twenty-one billion, two hundred thirty-two million, two hundred seventy-five thousand, four hundred fifty-six".