261225166 has 8 divisors (see below), whose sum is σ = 392460624. Its totient is φ = 130404960.

The previous prime is 261225163. The next prime is 261225197. The reversal of 261225166 is 661522162.

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 (261225163) 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, 102235 + ... + 104758.

It is an arithmetic number, because the mean of its divisors is an integer number (49057578).

Almost surely, 2^261225166 is an apocalyptic number.

261225166 is a deficient number, since it is larger than the sum of its proper divisors (131235458).

261225166 is a wasteful number, since it uses less digits than its factorization.

261225166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 207626.

The product of its digits is 8640, while the sum is 31.

The square root of 261225166 is about 16162.4616318183. The cubic root of 261225166 is about 639.2513756329.

The spelling of 261225166 in words is "two hundred sixty-one million, two hundred twenty-five thousand, one hundred sixty-six".