21039240260 has 48 divisors (see below), whose sum is σ = 44459543856. Its totient is φ = 8363077632.

The previous prime is 21039240259. The next prime is 21039240281. The reversal of 21039240260 is 6204293012.

It can be written as a sum of positive squares in 8 ways, for example, as 9945673984 + 11093566276 = 99728^2 + 105326^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2104634 + ... + 2114606.

It is an arithmetic number, because the mean of its divisors is an integer number (926240497).

Almost surely, 2^21039240260 is an apocalyptic number.

21039240260 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21039240260 is an abundant number, since it is smaller than the sum of its proper divisors (23420303596).

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

21039240260 is a wasteful number, since it uses less digits than its factorization.

21039240260 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10632 (or 10630 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 29.

The spelling of 21039240260 in words is "twenty-one billion, thirty-nine million, two hundred forty thousand, two hundred sixty".