21140042540 has 12 divisors (see below), whose sum is σ = 44394089376. Its totient is φ = 8456017008.

The previous prime is 21140042503. The next prime is 21140042563. The reversal of 21140042540 is 4524004112.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 528501044 + ... + 528501083.

It is an arithmetic number, because the mean of its divisors is an integer number (3699507448).

Almost surely, 2^21140042540 is an apocalyptic number.

21140042540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21140042540 is an abundant number, since it is smaller than the sum of its proper divisors (23254046836).

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

21140042540 is a wasteful number, since it uses less digits than its factorization.

21140042540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1057002136 (or 1057002134 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 23.

Adding to 21140042540 its reverse (4524004112), we get a palindrome (25664046652).

The spelling of 21140042540 in words is "twenty-one billion, one hundred forty million, forty-two thousand, five hundred forty".