21540901759 has 16 divisors (see below), whose sum is σ = 23347072224. Its totient is φ = 19756195200.

The previous prime is 21540901751. The next prime is 21540901783. The reversal of 21540901759 is 95710904512.

It is a cyclic number.

It is not a de Polignac number, because 21540901759 - 2³ = 21540901751 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21540901751) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6770149 + ... + 6773329.

It is an arithmetic number, because the mean of its divisors is an integer number (1459192014).

Almost surely, 2^21540901759 is an apocalyptic number.

21540901759 is a deficient number, since it is larger than the sum of its proper divisors (1806170465).

21540901759 is a wasteful number, since it uses less digits than its factorization.

21540901759 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6378.

The product of its (nonzero) digits is 113400, while the sum is 43.

The spelling of 21540901759 in words is "twenty-one billion, five hundred forty million, nine hundred one thousand, seven hundred fifty-nine".