261206178 has 8 divisors (see below), whose sum is σ = 522412368. Its totient is φ = 87068724.

The previous prime is 261206177. The next prime is 261206221. The reversal of 261206178 is 871602162.

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

261206178 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (261206171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21767176 + ... + 21767187.

It is an arithmetic number, because the mean of its divisors is an integer number (65301546).

Almost surely, 2^261206178 is an apocalyptic number.

261206178 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261206178 is a wasteful number, since it uses less digits than its factorization.

261206178 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43534368.

The product of its (nonzero) digits is 8064, while the sum is 33.

The square root of 261206178 is about 16161.8742106230. The cubic root of 261206178 is about 639.2358865698.

The spelling of 261206178 in words is "two hundred sixty-one million, two hundred six thousand, one hundred seventy-eight".