6561667770 has 32 divisors (see below), whose sum is σ = 17997717888. Its totient is φ = 1499809728.

The previous prime is 6561667733. The next prime is 6561667771. The reversal of 6561667770 is 777661656.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (6561667771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15622809 + ... + 15623228.

It is an arithmetic number, because the mean of its divisors is an integer number (562428684).

Almost surely, 2^6561667770 is an apocalyptic number.

6561667770 is an abundant number, since it is smaller than the sum of its proper divisors (11436050118).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6561667770 is a wasteful number, since it uses less digits than its factorization.

6561667770 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31246054.

The product of its (nonzero) digits is 2222640, while the sum is 51.

The square root of 6561667770 is about 81004.1219321585. The cubic root of 6561667770 is about 1872.1389510555.

It can be divided in two parts, 65616 and 67770, that added together give a triangular number (133386 = T₅₁₆).

The spelling of 6561667770 in words is "six billion, five hundred sixty-one million, six hundred sixty-seven thousand, seven hundred seventy".