6561385945 has 8 divisors (see below), whose sum is σ = 7876407744. Its totient is φ = 5247279024.

The previous prime is 6561385913. The next prime is 6561385949. The reversal of 6561385945 is 5495831656.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 6561385945 - 2⁵ = 6561385913 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 6561385892 and 6561385901.

It is not an unprimeable number, because it can be changed into a prime (6561385949) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 212839 + ... + 241708.

It is an arithmetic number, because the mean of its divisors is an integer number (984550968).

Almost surely, 2^6561385945 is an apocalyptic number.

It is an amenable number.

6561385945 is a deficient number, since it is larger than the sum of its proper divisors (1315021799).

6561385945 is a wasteful number, since it uses less digits than its factorization.

6561385945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 457439.

The product of its digits is 3888000, while the sum is 52.

The square root of 6561385945 is about 81002.3823415089. The cubic root of 6561385945 is about 1872.1121477522.

The spelling of 6561385945 in words is "six billion, five hundred sixty-one million, three hundred eighty-five thousand, nine hundred forty-five".