640476636166 has 4 divisors (see below), whose sum is σ = 960714954252. Its totient is φ = 320238318082.

The previous prime is 640476636067. The next prime is 640476636167. The reversal of 640476636166 is 661636674046.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640476636167) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160119159040 + ... + 160119159043.

It is an arithmetic number, because the mean of its divisors is an integer number (240178738563).

Almost surely, 2^640476636166 is an apocalyptic number.

640476636166 is a deficient number, since it is larger than the sum of its proper divisors (320238318086).

640476636166 is a wasteful number, since it uses less digits than its factorization.

640476636166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 320238318085.

The product of its (nonzero) digits is 15676416, while the sum is 55.

The spelling of 640476636166 in words is "six hundred forty billion, four hundred seventy-six million, six hundred thirty-six thousand, one hundred sixty-six".