261665044457732 has 12 divisors (see below), whose sum is σ = 473703959794380. Its totient is φ = 126321055945056.

The previous prime is 261665044457701. The next prime is 261665044457837. The reversal of 261665044457732 is 237754440566162.

It can be written as a sum of positive squares in 2 ways, for example, as 113987524132036 + 147677520325696 = 10676494^2 + 12152264^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1127866570823 + ... + 1127866571054.

It is an arithmetic number, because the mean of its divisors is an integer number (39475329982865).

Almost surely, 2^{261665044457732} is an apocalyptic number.

It is an amenable number.

261665044457732 is a deficient number, since it is larger than the sum of its proper divisors (212038915336648).

261665044457732 is a wasteful number, since it uses less digits than its factorization.

261665044457732 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2255733141910 (or 2255733141908 counting only the distinct ones).

The product of its (nonzero) digits is 203212800, while the sum is 62.

The spelling of 261665044457732 in words is "two hundred sixty-one trillion, six hundred sixty-five billion, forty-four million, four hundred fifty-seven thousand, seven hundred thirty-two".