6640204664641 has 4 divisors (see below), whose sum is σ = 6641506926000. Its totient is φ = 6638902403284.

The previous prime is 6640204664593. The next prime is 6640204664657. The reversal of 6640204664641 is 1464664020466.

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 not a de Polignac number, because 6640204664641 - 2²⁷ = 6640070446913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6640204664941) 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, 651123031 + ... + 651133228.

It is an arithmetic number, because the mean of its divisors is an integer number (1660376731500).

Almost surely, 2^{6640204664641} is an apocalyptic number.

It is an amenable number.

6640204664641 is a deficient number, since it is larger than the sum of its proper divisors (1302261359).

6640204664641 is a wasteful number, since it uses less digits than its factorization.

6640204664641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1302261358.

The product of its (nonzero) digits is 3981312, while the sum is 49.

The spelling of 6640204664641 in words is "six trillion, six hundred forty billion, two hundred four million, six hundred sixty-four thousand, six hundred forty-one".