20185138807 has 4 divisors (see below), whose sum is σ = 20195248536. Its totient is φ = 20175029080.

The previous prime is 20185138781. The next prime is 20185138817. The reversal of 20185138807 is 70883158102.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 70883158102 = 2 ⋅35441579051.

It is a cyclic number.

It is not a de Polignac number, because 20185138807 - 2¹¹ = 20185136759 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 (20185138817) 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, 5051869 + ... + 5055862.

It is an arithmetic number, because the mean of its divisors is an integer number (5048812134).

Almost surely, 2^20185138807 is an apocalyptic number.

20185138807 is a deficient number, since it is larger than the sum of its proper divisors (10109729).

20185138807 is a wasteful number, since it uses less digits than its factorization.

20185138807 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10109728.

The product of its (nonzero) digits is 107520, while the sum is 43.

The spelling of 20185138807 in words is "twenty billion, one hundred eighty-five million, one hundred thirty-eight thousand, eight hundred seven".