20525543405 has 4 divisors (see below), whose sum is σ = 24630652092. Its totient is φ = 16420434720.

The previous prime is 20525543399. The next prime is 20525543407. The reversal of 20525543405 is 50434552502.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3454030441 + 17071512964 = 58771^2 + 130658^2 .

It is not a de Polignac number, because 20525543405 - 2¹⁰ = 20525542381 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 (20525543407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2052554336 + ... + 2052554345.

It is an arithmetic number, because the mean of its divisors is an integer number (6157663023).

Almost surely, 2^20525543405 is an apocalyptic number.

It is an amenable number.

20525543405 is a deficient number, since it is larger than the sum of its proper divisors (4105108687).

20525543405 is an equidigital number, since it uses as much as digits as its factorization.

20525543405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4105108686.

The product of its (nonzero) digits is 120000, while the sum is 35.

The spelling of 20525543405 in words is "twenty billion, five hundred twenty-five million, five hundred forty-three thousand, four hundred five".