661118361 has 8 divisors (see below), whose sum is σ = 882208704. Its totient is φ = 440386800.

The previous prime is 661118351. The next prime is 661118363. The reversal of 661118361 is 163811166.

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

It is not a de Polignac number, because 661118361 - 2⁵ = 661118329 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (661118363) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 85365 + ... + 92786.

It is an arithmetic number, because the mean of its divisors is an integer number (110276088).

Almost surely, 2^661118361 is an apocalyptic number.

It is an amenable number.

661118361 is a deficient number, since it is larger than the sum of its proper divisors (221090343).

661118361 is a wasteful number, since it uses less digits than its factorization.

661118361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 179391.

The product of its digits is 5184, while the sum is 33.

The square root of 661118361 is about 25712.2220159985. Note that the first 3 decimals coincide. The cubic root of 661118361 is about 871.1502647481.

The spelling of 661118361 in words is "six hundred sixty-one million, one hundred eighteen thousand, three hundred sixty-one".