261665642315703 has 8 divisors (see below), whose sum is σ = 352484301676528. Its totient is φ = 172645372249344.

The previous prime is 261665642315689. The next prime is 261665642315731. The reversal of 261665642315703 is 307513246566162.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 261665642315703 - 2²² = 261665638121399 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261665642415703) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 449597323276 + ... + 449597323857.

It is an arithmetic number, because the mean of its divisors is an integer number (44060537709566).

Almost surely, 2^{261665642315703} is an apocalyptic number.

261665642315703 is a deficient number, since it is larger than the sum of its proper divisors (90818659360825).

261665642315703 is an equidigital number, since it uses as much as digits as its factorization.

261665642315703 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 899194647233.

The product of its (nonzero) digits is 32659200, while the sum is 57.

The spelling of 261665642315703 in words is "two hundred sixty-one trillion, six hundred sixty-five billion, six hundred forty-two million, three hundred fifteen thousand, seven hundred three".