21002340540 has 48 divisors (see below), whose sum is σ = 58825654272. Its totient is φ = 5598805056.

The previous prime is 21002340529. The next prime is 21002340563. The reversal of 21002340540 is 4504320012.

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, 134757 + ... + 245283.

It is an arithmetic number, because the mean of its divisors is an integer number (1225534464).

Almost surely, 2^21002340540 is an apocalyptic number.

21002340540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21002340540 is an abundant number, since it is smaller than the sum of its proper divisors (37823313732).

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

21002340540 is a wasteful number, since it uses less digits than its factorization.

21002340540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113706 (or 113704 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 21.

Adding to 21002340540 its reverse (4504320012), we get a palindrome (25506660552).

The spelling of 21002340540 in words is "twenty-one billion, two million, three hundred forty thousand, five hundred forty".