20508860139 has 4 divisors (see below), whose sum is σ = 27345146856. Its totient is φ = 13672573424.

The previous prime is 20508860101. The next prime is 20508860173. The reversal of 20508860139 is 93106880502.

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 20508860139 - 2⁸ = 20508859883 is a prime.

It is a super-2 number, since 2×20508860139² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20508860139.

It is not an unprimeable number, because it can be changed into a prime (20508864139) 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, 3418143354 + ... + 3418143359.

It is an arithmetic number, because the mean of its divisors is an integer number (6836286714).

Almost surely, 2^20508860139 is an apocalyptic number.

20508860139 is a deficient number, since it is larger than the sum of its proper divisors (6836286717).

20508860139 is an equidigital number, since it uses as much as digits as its factorization.

20508860139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6836286716.

The product of its (nonzero) digits is 103680, while the sum is 42.

The spelling of 20508860139 in words is "twenty billion, five hundred eight million, eight hundred sixty thousand, one hundred thirty-nine".