261149766 has 32 divisors (see below), whose sum is σ = 550637568. Its totient is φ = 82446720.

The previous prime is 261149761. The next prime is 261149821. The reversal of 261149766 is 667941162.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261149761) 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 15 ways as a sum of consecutive naturals, for example, 6195 + ... + 23678.

It is an arithmetic number, because the mean of its divisors is an integer number (17207424).

Almost surely, 2^261149766 is an apocalyptic number.

261149766 is an abundant number, since it is smaller than the sum of its proper divisors (289487802).

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

261149766 is a wasteful number, since it uses less digits than its factorization.

261149766 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29956.

The product of its digits is 108864, while the sum is 42.

The square root of 261149766 is about 16160.1288980008. The cubic root of 261149766 is about 639.1898652348.

The spelling of 261149766 in words is "two hundred sixty-one million, one hundred forty-nine thousand, seven hundred sixty-six".