21540045505 has 32 divisors (see below), whose sum is σ = 28533875328. Its totient is φ = 15608767680.

The previous prime is 21540045463. The next prime is 21540045523. The reversal of 21540045505 is 50554004512.

It is not a de Polignac number, because 21540045505 - 2¹³ = 21540037313 is a prime.

It is a Duffinian number.

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 31 ways as a sum of consecutive naturals, for example, 1877647 + ... + 1889083.

It is an arithmetic number, because the mean of its divisors is an integer number (891683604).

Almost surely, 2^21540045505 is an apocalyptic number.

It is an amenable number.

21540045505 is a deficient number, since it is larger than the sum of its proper divisors (6993829823).

21540045505 is a wasteful number, since it uses less digits than its factorization.

21540045505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11758 (or 11736 counting only the distinct ones).

The product of its (nonzero) digits is 20000, while the sum is 31.

The spelling of 21540045505 in words is "twenty-one billion, five hundred forty million, forty-five thousand, five hundred five".