661101165 has 12 divisors (see below), whose sum is σ = 1145908764. Its totient is φ = 352587264.

The previous prime is 661101149. The next prime is 661101169. The reversal of 661101165 is 561101166.

It can be written as a sum of positive squares in 2 ways, for example, as 341621289 + 319479876 = 18483^2 + 17874^2 .

It is not a de Polignac number, because 661101165 - 2⁴ = 661101149 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661101169) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7345524 + ... + 7345613.

It is an arithmetic number, because the mean of its divisors is an integer number (95492397).

Almost surely, 2^661101165 is an apocalyptic number.

It is an amenable number.

661101165 is a deficient number, since it is larger than the sum of its proper divisors (484807599).

661101165 is a wasteful number, since it uses less digits than its factorization.

661101165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14691148 (or 14691145 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 27.

The square root of 661101165 is about 25711.8876203207. The cubic root of 661101165 is about 871.1427116731.

Subtracting from 661101165 its reverse (561101166), we obtain a palindrome (99999999).

The spelling of 661101165 in words is "six hundred sixty-one million, one hundred one thousand, one hundred sixty-five".