261992231135 has 4 divisors (see below), whose sum is σ = 314390677368. Its totient is φ = 209593784904.

The previous prime is 261992231131. The next prime is 261992231173. The reversal of 261992231135 is 531132299162.

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 261992231135 - 2² = 261992231131 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 (261992231131) 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, 26199223109 + ... + 26199223118.

It is an arithmetic number, because the mean of its divisors is an integer number (78597669342).

Almost surely, 2^261992231135 is an apocalyptic number.

261992231135 is a deficient number, since it is larger than the sum of its proper divisors (52398446233).

261992231135 is an equidigital number, since it uses as much as digits as its factorization.

261992231135 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52398446232.

The product of its digits is 174960, while the sum is 44.

The spelling of 261992231135 in words is "two hundred sixty-one billion, nine hundred ninety-two million, two hundred thirty-one thousand, one hundred thirty-five".