261049923361 has 4 divisors (see below), whose sum is σ = 261573070000. Its totient is φ = 260526776724.

The previous prime is 261049923359. The next prime is 261049923389. The reversal of 261049923361 is 163329940162.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 261049923361 - 2¹ = 261049923359 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261049923391) 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, 261572571 + ... + 261573568.

It is an arithmetic number, because the mean of its divisors is an integer number (65393267500).

Almost surely, 2^261049923361 is an apocalyptic number.

It is an amenable number.

261049923361 is a deficient number, since it is larger than the sum of its proper divisors (523146639).

261049923361 is an equidigital number, since it uses as much as digits as its factorization.

261049923361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 523146638.

The product of its (nonzero) digits is 419904, while the sum is 46.

The spelling of 261049923361 in words is "two hundred sixty-one billion, forty-nine million, nine hundred twenty-three thousand, three hundred sixty-one".