261646663035366 has 40 divisors (see below), whose sum is σ = 670036957194000. Its totient is φ = 74756189438352.

The previous prime is 261646663035347. The next prime is 261646663035371. The reversal of 261646663035366 is 663530366646162.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 115364488741 + ... + 115364491008.

It is an arithmetic number, because the mean of its divisors is an integer number (16750923929850).

Almost surely, 2^{261646663035366} is an apocalyptic number.

261646663035366 is an abundant number, since it is smaller than the sum of its proper divisors (408390294158634).

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

261646663035366 is a wasteful number, since it uses less digits than its factorization.

261646663035366 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 230728979770 (or 230728979761 counting only the distinct ones).

The product of its (nonzero) digits is 302330880, while the sum is 63.

The spelling of 261646663035366 in words is "two hundred sixty-one trillion, six hundred forty-six billion, six hundred sixty-three million, thirty-five thousand, three hundred sixty-six".