6543645965 has 4 divisors (see below), whose sum is σ = 7852375164. Its totient is φ = 5234916768.

The previous prime is 6543645949. The next prime is 6543646013. The reversal of 6543645965 is 5695463456.

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 4909384489 + 1634261476 = 70067^2 + 40426^2 .

It is a cyclic number.

It is not a de Polignac number, because 6543645965 - 2⁴ = 6543645949 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 654364592 + ... + 654364601.

It is an arithmetic number, because the mean of its divisors is an integer number (1963093791).

Almost surely, 2^6543645965 is an apocalyptic number.

It is an amenable number.

6543645965 is a deficient number, since it is larger than the sum of its proper divisors (1308729199).

6543645965 is a wasteful number, since it uses less digits than its factorization.

6543645965 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1308729198.

The product of its digits is 11664000, while the sum is 53.

The square root of 6543645965 is about 80892.8053970191. The cubic root of 6543645965 is about 1870.4234187560.

The spelling of 6543645965 in words is "six billion, five hundred forty-three million, six hundred forty-five thousand, nine hundred sixty-five".