261315166 has 8 divisors (see below), whose sum is σ = 447968880. Its totient is φ = 111992208.

The previous prime is 261315163. The next prime is 261315193. The reversal of 261315166 is 661513162.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261315161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9332671 + ... + 9332698.

It is an arithmetic number, because the mean of its divisors is an integer number (55996110).

Almost surely, 2^261315166 is an apocalyptic number.

261315166 is a deficient number, since it is larger than the sum of its proper divisors (186653714).

261315166 is a wasteful number, since it uses less digits than its factorization.

261315166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18665378.

The product of its digits is 6480, while the sum is 31.

The square root of 261315166 is about 16165.2456213941. The cubic root of 261315166 is about 639.3247810386.

The spelling of 261315166 in words is "two hundred sixty-one million, three hundred fifteen thousand, one hundred sixty-six".