20540588639 has 4 divisors (see below), whose sum is σ = 20554293000. Its totient is φ = 20526884280.

The previous prime is 20540588581. The next prime is 20540588683. The reversal of 20540588639 is 93688504502.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20540588639 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 (20540588839) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6849932 + ... + 6852929.

It is an arithmetic number, because the mean of its divisors is an integer number (5138573250).

Almost surely, 2^20540588639 is an apocalyptic number.

20540588639 is a deficient number, since it is larger than the sum of its proper divisors (13704361).

20540588639 is a wasteful number, since it uses less digits than its factorization.

20540588639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13704360.

The product of its (nonzero) digits is 2073600, while the sum is 50.

The spelling of 20540588639 in words is "twenty billion, five hundred forty million, five hundred eighty-eight thousand, six hundred thirty-nine".