661110113 has 4 divisors (see below), whose sum is σ = 664535748. Its totient is φ = 657684480.

The previous prime is 661110031. The next prime is 661110143. The reversal of 661110113 is 311011166.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 311011166 = 2 ⋅155505583.

It can be written as a sum of positive squares in 2 ways, for example, as 170354704 + 490755409 = 13052^2 + 22153^2 .

It is a cyclic number.

It is not a de Polignac number, because 661110113 - 2¹⁴ = 661093729 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (661110143) 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, 1712528 + ... + 1712913.

It is an arithmetic number, because the mean of its divisors is an integer number (166133937).

Almost surely, 2^661110113 is an apocalyptic number.

It is an amenable number.

661110113 is a deficient number, since it is larger than the sum of its proper divisors (3425635).

661110113 is a wasteful number, since it uses less digits than its factorization.

661110113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3425634.

The product of its (nonzero) digits is 108, while the sum is 20.

The square root of 661110113 is about 25712.0616248484. The cubic root of 661110113 is about 871.1466419590.

Adding to 661110113 its reverse (311011166), we get a palindrome (972121279).

The spelling of 661110113 in words is "six hundred sixty-one million, one hundred ten thousand, one hundred thirteen".