661110011 has 4 divisors (see below), whose sum is σ = 661185552. Its totient is φ = 661034472.

The previous prime is 661109989. The next prime is 661110017. The reversal of 661110011 is 110011166.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 110011166 = 2 ⋅55005583.

It is a cyclic number.

It is not a de Polignac number, because 661110011 - 2²⁶ = 594001147 is a prime.

It is a Duffinian number.

It is a zygodrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (661110017) 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, 22616 + ... + 42821.

It is an arithmetic number, because the mean of its divisors is an integer number (165296388).

Almost surely, 2^661110011 is an apocalyptic number.

661110011 is a deficient number, since it is larger than the sum of its proper divisors (75541).

661110011 is a wasteful number, since it uses less digits than its factorization.

661110011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75540.

The product of its (nonzero) digits is 36, while the sum is 17.

The square root of 661110011 is about 25712.0596413434. The cubic root of 661110011 is about 871.1465971571.

Adding to 661110011 its reverse (110011166), we get a palindrome (771121177).

The spelling of 661110011 in words is "six hundred sixty-one million, one hundred ten thousand, eleven".