20042640539 has 4 divisors (see below), whose sum is σ = 20043024456. Its totient is φ = 20042256624.

The previous prime is 20042640533. The next prime is 20042640571. The reversal of 20042640539 is 93504624002.

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

It is a cyclic number.

It is not a de Polignac number, because 20042640539 - 2²⁰ = 20041591963 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20042640499 and 20042640508.

It is not an unprimeable number, because it can be changed into a prime (20042640533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 98474 + ... + 223119.

It is an arithmetic number, because the mean of its divisors is an integer number (5010756114).

Almost surely, 2^20042640539 is an apocalyptic number.

20042640539 is a deficient number, since it is larger than the sum of its proper divisors (383917).

20042640539 is an equidigital number, since it uses as much as digits as its factorization.

20042640539 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 383916.

The product of its (nonzero) digits is 51840, while the sum is 35.

The spelling of 20042640539 in words is "twenty billion, forty-two million, six hundred forty thousand, five hundred thirty-nine".