6561226660201 has 4 divisors (see below), whose sum is σ = 6562121420932. Its totient is φ = 6560331899472.

The previous prime is 6561226660193. The next prime is 6561226660243. The reversal of 6561226660201 is 1020666221656.

It is a happy number.

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 1453857177600 + 5107369482601 = 1205760^2 + 2259949^2 .

It is a cyclic number.

It is not a de Polignac number, because 6561226660201 - 2³ = 6561226660193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6561226660501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 447369366 + ... + 447384031.

It is an arithmetic number, because the mean of its divisors is an integer number (1640530355233).

Almost surely, 2^{6561226660201} is an apocalyptic number.

It is an amenable number.

6561226660201 is a deficient number, since it is larger than the sum of its proper divisors (894760731).

6561226660201 is an equidigital number, since it uses as much as digits as its factorization.

6561226660201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 894760730.

The product of its (nonzero) digits is 311040, while the sum is 43.

The spelling of 6561226660201 in words is "six trillion, five hundred sixty-one billion, two hundred twenty-six million, six hundred sixty thousand, two hundred one".