1640665678177 has 4 divisors (see below), whose sum is σ = 1651115778196. Its totient is φ = 1630215578160.

The previous prime is 1640665678133. The next prime is 1640665678193. The reversal of 1640665678177 is 7718765660461.

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 1204833327201 + 435832350976 = 1097649^2 + 660176^2 .

It is a cyclic number.

It is not a de Polignac number, because 1640665678177 - 2⁷ = 1640665678049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1640665678117) 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, 5225049774 + ... + 5225050087.

It is an arithmetic number, because the mean of its divisors is an integer number (412778944549).

Almost surely, 2^{1640665678177} is an apocalyptic number.

It is an amenable number.

1640665678177 is a deficient number, since it is larger than the sum of its proper divisors (10450100019).

1640665678177 is a wasteful number, since it uses less digits than its factorization.

1640665678177 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10450100018.

The product of its (nonzero) digits is 71124480, while the sum is 64.

The spelling of 1640665678177 in words is "one trillion, six hundred forty billion, six hundred sixty-five million, six hundred seventy-eight thousand, one hundred seventy-seven".