661066440111 has 72 divisors (see below), whose sum is σ = 1283030343504. Its totient is φ = 323210442240.

The previous prime is 661066440079. The next prime is 661066440161. The reversal of 661066440111 is 111044660166.

661066440111 is a `hidden beast` number, since 6 + 6 + 1 + 0 + 6 + 644 + 0 + 1 + 1 + 1 = 666.

It is not a de Polignac number, because 661066440111 - 2⁵ = 661066440079 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661066440161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 3925600 + ... + 4090533.

It is an arithmetic number, because the mean of its divisors is an integer number (17819865882).

Almost surely, 2^661066440111 is an apocalyptic number.

661066440111 is a deficient number, since it is larger than the sum of its proper divisors (621963903393).

661066440111 is a wasteful number, since it uses less digits than its factorization.

661066440111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8016181 (or 8016171 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The spelling of 661066440111 in words is "six hundred sixty-one billion, sixty-six million, four hundred forty thousand, one hundred eleven".