20178395137 has 4 divisors (see below), whose sum is σ = 20178729220. Its totient is φ = 20178061056.

The previous prime is 20178395131. The next prime is 20178395173. The reversal of 20178395137 is 73159387102.

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

It can be written as a sum of positive squares in 2 ways, for example, as 11684745216 + 8493649921 = 108096^2 + 92161^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20178395137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20178395131) 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, 48312 + ... + 206617.

It is an arithmetic number, because the mean of its divisors is an integer number (5044682305).

Almost surely, 2^20178395137 is an apocalyptic number.

It is an amenable number.

20178395137 is a deficient number, since it is larger than the sum of its proper divisors (334083).

20178395137 is an equidigital number, since it uses as much as digits as its factorization.

20178395137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 334082.

The product of its (nonzero) digits is 317520, while the sum is 46.

The spelling of 20178395137 in words is "twenty billion, one hundred seventy-eight million, three hundred ninety-five thousand, one hundred thirty-seven".