6561870355366 has 4 divisors (see below), whose sum is σ = 9842805533052. Its totient is φ = 3280935177682.

The previous prime is 6561870355307. The next prime is 6561870355367. The reversal of 6561870355366 is 6635530781656.

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

It is a super-2 number, since 2×6561870355366² (a number of 26 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6561870355367) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1640467588840 + ... + 1640467588843.

It is an arithmetic number, because the mean of its divisors is an integer number (2460701383263).

Almost surely, 2^{6561870355366} is an apocalyptic number.

6561870355366 is a deficient number, since it is larger than the sum of its proper divisors (3280935177686).

6561870355366 is a wasteful number, since it uses less digits than its factorization.

6561870355366 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3280935177685.

The product of its (nonzero) digits is 81648000, while the sum is 61.

The spelling of 6561870355366 in words is "six trillion, five hundred sixty-one billion, eight hundred seventy million, three hundred fifty-five thousand, three hundred sixty-six".