21663012533240 has 64 divisors (see below), whose sum is σ = 52521648298560. Its totient is φ = 7994002775040.

The previous prime is 21663012533237. The next prime is 21663012533293. The reversal of 21663012533240 is 4233521036612.

It is a super-2 number, since 2×21663012533240² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21663012533194 and 21663012533203.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11208404 + ... + 12998243.

It is an arithmetic number, because the mean of its divisors is an integer number (820650754665).

Almost surely, 2^{21663012533240} is an apocalyptic number.

21663012533240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21663012533240 is an abundant number, since it is smaller than the sum of its proper divisors (30858635765320).

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

21663012533240 is a wasteful number, since it uses less digits than its factorization.

21663012533240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24208392 (or 24208388 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 38.

Adding to 21663012533240 its reverse (4233521036612), we get a palindrome (25896533569852).

The spelling of 21663012533240 in words is "twenty-one trillion, six hundred sixty-three billion, twelve million, five hundred thirty-three thousand, two hundred forty".