261533601726205 has 8 divisors (see below), whose sum is σ = 319761837582552. Its totient is φ = 205279204373568.

The previous prime is 261533601726197. The next prime is 261533601726227. The reversal of 261533601726205 is 502627106335162.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 24369012504004 + 237164589222201 = 4936498^2 + 15400149^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 261533601726205 - 2³ = 261533601726197 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 493459625634 + ... + 493459626163.

It is an arithmetic number, because the mean of its divisors is an integer number (39970229697819).

Almost surely, 2^{261533601726205} is an apocalyptic number.

It is an amenable number.

261533601726205 is a deficient number, since it is larger than the sum of its proper divisors (58228235856347).

261533601726205 is an equidigital number, since it uses as much as digits as its factorization.

261533601726205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 986919251855.

The product of its (nonzero) digits is 2721600, while the sum is 49.

The spelling of 261533601726205 in words is "two hundred sixty-one trillion, five hundred thirty-three billion, six hundred one million, seven hundred twenty-six thousand, two hundred five".