6561578495 has 4 divisors (see below), whose sum is σ = 7873894200. Its totient is φ = 5249262792.

The previous prime is 6561578461. The next prime is 6561578509. The reversal of 6561578495 is 5948751656.

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

It is a cyclic number.

It is not a de Polignac number, because 6561578495 - 2¹⁸ = 6561316351 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 6561578495.

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, 656157845 + ... + 656157854.

It is an arithmetic number, because the mean of its divisors is an integer number (1968473550).

Almost surely, 2^6561578495 is an apocalyptic number.

6561578495 is a deficient number, since it is larger than the sum of its proper divisors (1312315705).

6561578495 is a wasteful number, since it uses less digits than its factorization.

6561578495 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1312315704.

The product of its digits is 9072000, while the sum is 56.

The square root of 6561578495 is about 81003.5708780792. The cubic root of 6561578495 is about 1872.1304605330.

The spelling of 6561578495 in words is "six billion, five hundred sixty-one million, five hundred seventy-eight thousand, four hundred ninety-five".