20544521405 has 4 divisors (see below), whose sum is σ = 24653425692. Its totient is φ = 16435617120.

The previous prime is 20544521279. The next prime is 20544521429. The reversal of 20544521405 is 50412544502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50412544502 = 2 ⋅25206272251.

It can be written as a sum of positive squares in 2 ways, for example, as 9075610756 + 11468910649 = 95266^2 + 107093^2 .

It is a de Polignac number, because none of the positive numbers 2^k-20544521405 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2054452136 + ... + 2054452145.

It is an arithmetic number, because the mean of its divisors is an integer number (6163356423).

Almost surely, 2^20544521405 is an apocalyptic number.

It is an amenable number.

20544521405 is a deficient number, since it is larger than the sum of its proper divisors (4108904287).

20544521405 is an equidigital number, since it uses as much as digits as its factorization.

20544521405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4108904286.

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

The spelling of 20544521405 in words is "twenty billion, five hundred forty-four million, five hundred twenty-one thousand, four hundred five".