261320066 has 16 divisors (see below), whose sum is σ = 467455104. Its totient is φ = 107124864.

The previous prime is 261320029. The next prime is 261320077. The reversal of 261320066 is 660023162.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 405455 + ... + 406098.

It is an arithmetic number, because the mean of its divisors is an integer number (29215944).

Almost surely, 2^261320066 is an apocalyptic number.

261320066 is a deficient number, since it is larger than the sum of its proper divisors (206135038).

261320066 is a wasteful number, since it uses less digits than its factorization.

261320066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 811585.

The product of its (nonzero) digits is 2592, while the sum is 26.

The square root of 261320066 is about 16165.3971803974. The cubic root of 261320066 is about 639.3287770713.

The spelling of 261320066 in words is "two hundred sixty-one million, three hundred twenty thousand, sixty-six".