661166011 has 8 divisors (see below), whose sum is σ = 722597184. Its totient is φ = 599955720.

The previous prime is 661166003. The next prime is 661166021. The reversal of 661166011 is 110661166.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 661166011 - 2³ = 661166003 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661166021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 48925 + ... + 60958.

It is an arithmetic number, because the mean of its divisors is an integer number (90324648).

Almost surely, 2^661166011 is an apocalyptic number.

661166011 is a deficient number, since it is larger than the sum of its proper divisors (61431173).

661166011 is a wasteful number, since it uses less digits than its factorization.

661166011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110441.

The product of its (nonzero) digits is 1296, while the sum is 28.

The square root of 661166011 is about 25713.1486014451. The cubic root of 661166011 is about 871.1711935839.

It can be divided in two parts, 66116 and 6011, that added together give a palindrome (72127).

The spelling of 661166011 in words is "six hundred sixty-one million, one hundred sixty-six thousand, eleven".