20887806139 has 4 divisors (see below), whose sum is σ = 21122500680. Its totient is φ = 20653111600.

The previous prime is 20887806127. The next prime is 20887806151. The reversal of 20887806139 is 93160878802.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 93160878802 = 2 ⋅46580439401.

It is an interprime number because it is at equal distance from previous prime (20887806127) and next prime (20887806151).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20887806139 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20887806739) 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, 117347137 + ... + 117347314.

It is an arithmetic number, because the mean of its divisors is an integer number (5280625170).

Almost surely, 2^20887806139 is an apocalyptic number.

20887806139 is a deficient number, since it is larger than the sum of its proper divisors (234694541).

20887806139 is an equidigital number, since it uses as much as digits as its factorization.

20887806139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 234694540.

The product of its (nonzero) digits is 1161216, while the sum is 52.

The spelling of 20887806139 in words is "twenty billion, eight hundred eighty-seven million, eight hundred six thousand, one hundred thirty-nine".