261646133240764 has 24 divisors (see below), whose sum is σ = 459623660126400. Its totient is φ = 130325173773120.

The previous prime is 261646133240741. The next prime is 261646133240797. The reversal of 261646133240764 is 467042331646162.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1356634 + ... + 22915774.

It is an arithmetic number, because the mean of its divisors is an integer number (19150985838600).

Almost surely, 2^{261646133240764} is an apocalyptic number.

It is an amenable number.

261646133240764 is a deficient number, since it is larger than the sum of its proper divisors (197977526885636).

261646133240764 is a wasteful number, since it uses less digits than its factorization.

261646133240764 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21570693 (or 21570691 counting only the distinct ones).

The product of its (nonzero) digits is 20901888, while the sum is 55.

The spelling of 261646133240764 in words is "two hundred sixty-one trillion, six hundred forty-six billion, one hundred thirty-three million, two hundred forty thousand, seven hundred sixty-four".