6500500605661 has 4 divisors (see below), whose sum is σ = 6500828718172. Its totient is φ = 6500172493152.

The previous prime is 6500500605631. The next prime is 6500500605721. The reversal of 6500500605661 is 1665060050056.

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 3271417394436 + 3229083211225 = 1808706^2 + 1796965^2 .

It is a cyclic number.

It is not a de Polignac number, because 6500500605661 - 2⁵ = 6500500605629 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6500500605601) 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, 164026536 + ... + 164066161.

It is an arithmetic number, because the mean of its divisors is an integer number (1625207179543).

Almost surely, 2^{6500500605661} is an apocalyptic number.

It is an amenable number.

6500500605661 is a deficient number, since it is larger than the sum of its proper divisors (328112511).

6500500605661 is a wasteful number, since it uses less digits than its factorization.

6500500605661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 328112510.

The product of its (nonzero) digits is 162000, while the sum is 40.

The spelling of 6500500605661 in words is "six trillion, five hundred billion, five hundred million, six hundred five thousand, six hundred sixty-one".