261534442165063 has 4 divisors (see below), whose sum is σ = 262707242354368. Its totient is φ = 260361641975760.

The previous prime is 261534442165049. The next prime is 261534442165097. The reversal of 261534442165063 is 360561244435162.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 261534442165063 - 2⁹ = 261534442164551 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 261534442165063.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261534442165663) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 586400094318 + ... + 586400094763.

It is an arithmetic number, because the mean of its divisors is an integer number (65676810588592).

Almost surely, 2^{261534442165063} is an apocalyptic number.

261534442165063 is a deficient number, since it is larger than the sum of its proper divisors (1172800189305).

261534442165063 is a wasteful number, since it uses less digits than its factorization.

261534442165063 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1172800189304.

The product of its (nonzero) digits is 12441600, while the sum is 52.

The spelling of 261534442165063 in words is "two hundred sixty-one trillion, five hundred thirty-four billion, four hundred forty-two million, one hundred sixty-five thousand, sixty-three".