21530503113440 has 48 divisors (see below), whose sum is σ = 50969410153200. Its totient is φ = 8594661089280.

The previous prime is 21530503113409. The next prime is 21530503113473. The reversal of 21530503113440 is 4431130503512.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 21530503113397 and 21530503113406.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 136953665 + ... + 137110784.

It is an arithmetic number, because the mean of its divisors is an integer number (1061862711525).

Almost surely, 2^{21530503113440} is an apocalyptic number.

21530503113440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21530503113440 is an abundant number, since it is smaller than the sum of its proper divisors (29438907039760).

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

21530503113440 is a wasteful number, since it uses less digits than its factorization.

21530503113440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 274064955 (or 274064947 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 32.

Adding to 21530503113440 its reverse (4431130503512), we get a palindrome (25961633616952).

The spelling of 21530503113440 in words is "twenty-one trillion, five hundred thirty billion, five hundred three million, one hundred thirteen thousand, four hundred forty".