661254641041011 has 16 divisors (see below), whose sum is σ = 882131720966016. Its totient is φ = 440607003572736.

The previous prime is 661254641041009. The next prime is 661254641041019. The reversal of 661254641041011 is 110140146452166.

It is a happy number.

It is not a de Polignac number, because 661254641041011 - 2¹ = 661254641041009 is a prime.

It is not an unprimeable number, because it can be changed into a prime (661254641041019) 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 in 15 ways as a sum of consecutive naturals, for example, 288450036 + ... + 290733438.

It is an arithmetic number, because the mean of its divisors is an integer number (55133232560376).

Almost surely, 2^{661254641041011} is an apocalyptic number.

661254641041011 is a deficient number, since it is larger than the sum of its proper divisors (220877079925005).

661254641041011 is a wasteful number, since it uses less digits than its factorization.

661254641041011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2333602.

The product of its (nonzero) digits is 138240, while the sum is 42.

Adding to 661254641041011 its reverse (110140146452166), we get a palindrome (771394787493177).

The spelling of 661254641041011 in words is "six hundred sixty-one trillion, two hundred fifty-four billion, six hundred forty-one million, forty-one thousand, eleven".