21603020040 has 288 divisors, whose sum is σ = 82324270080. Its totient is φ = 4898444544.

The previous prime is 21603020039. The next prime is 21603020051. The reversal of 21603020040 is 4002030612.

It is a happy number.

21603020040 is a `hidden beast` number, since 2 + 1 + 603 + 0 + 20 + 0 + 40 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21603019995 and 21603020022.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 2235459 + ... + 2245101.

It is an arithmetic number, because the mean of its divisors is an integer number (285848160).

Almost surely, 2^21603020040 is an apocalyptic number.

21603020040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21603020040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41162135040).

21603020040 is an abundant number, since it is smaller than the sum of its proper divisors (60721250040).

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

21603020040 is a wasteful number, since it uses less digits than its factorization.

21603020040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9801 (or 9787 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

Adding to 21603020040 its reverse (4002030612), we get a palindrome (25605050652).

The spelling of 21603020040 in words is "twenty-one billion, six hundred three million, twenty thousand, forty".