21542522405 has 16 divisors (see below), whose sum is σ = 26288214768. Its totient is φ = 16942848000.

The previous prime is 21542522377. The next prime is 21542522437. The reversal of 21542522405 is 50422524512.

It can be written as a sum of positive squares in 8 ways, for example, as 3859639876 + 17682882529 = 62126^2 + 132977^2 .

It is not a de Polignac number, because 21542522405 - 2¹⁰ = 21542521381 is a prime.

It is a Duffinian number.

It is a Curzon number.

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, 617735 + ... + 651675.

It is an arithmetic number, because the mean of its divisors is an integer number (1643013423).

Almost surely, 2^21542522405 is an apocalyptic number.

It is an amenable number.

21542522405 is a deficient number, since it is larger than the sum of its proper divisors (4745692363).

21542522405 is a wasteful number, since it uses less digits than its factorization.

21542522405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36088.

The product of its (nonzero) digits is 32000, while the sum is 32.

The spelling of 21542522405 in words is "twenty-one billion, five hundred forty-two million, five hundred twenty-two thousand, four hundred five".