640186158161 has 4 divisors (see below), whose sum is σ = 698384899824. Its totient is φ = 581987416500.

The previous prime is 640186158107. The next prime is 640186158211. The reversal of 640186158161 is 161851681046.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-640186158161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (640186158961) 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, 29099370815 + ... + 29099370836.

It is an arithmetic number, because the mean of its divisors is an integer number (174596224956).

Almost surely, 2^640186158161 is an apocalyptic number.

It is an amenable number.

640186158161 is a deficient number, since it is larger than the sum of its proper divisors (58198741663).

640186158161 is a wasteful number, since it uses less digits than its factorization.

640186158161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58198741662.

The product of its (nonzero) digits is 276480, while the sum is 47.

The spelling of 640186158161 in words is "six hundred forty billion, one hundred eighty-six million, one hundred fifty-eight thousand, one hundred sixty-one".