21533631226440 has 64 divisors (see below), whose sum is σ = 65975380796160. Its totient is φ = 5620125027840.

The previous prime is 21533631226433. The next prime is 21533631226441. The reversal of 21533631226440 is 4462213633512.

It is a junction number, because it is equal to n+sod(n) for n = 21533631226392 and 21533631226401.

It is not an unprimeable number, because it can be changed into a prime (21533631226441) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1909004221 + ... + 1909015500.

It is an arithmetic number, because the mean of its divisors is an integer number (1030865324940).

Almost surely, 2^{21533631226440} is an apocalyptic number.

21533631226440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21533631226440 is an abundant number, since it is smaller than the sum of its proper divisors (44441749569720).

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

21533631226440 is a wasteful number, since it uses less digits than its factorization.

21533631226440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3818019782 (or 3818019778 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 42.

Adding to 21533631226440 its reverse (4462213633512), we get a palindrome (25995844859952).

The spelling of 21533631226440 in words is "twenty-one trillion, five hundred thirty-three billion, six hundred thirty-one million, two hundred twenty-six thousand, four hundred forty".