261161165143 has 4 divisors (see below), whose sum is σ = 276523586640. Its totient is φ = 245798743648.

The previous prime is 261161165119. The next prime is 261161165147. The reversal of 261161165143 is 341561161162.

It is a happy number.

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 261161165143 - 2²¹ = 261159067991 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 (261161165147) 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, 7681210723 + ... + 7681210756.

It is an arithmetic number, because the mean of its divisors is an integer number (69130896660).

Almost surely, 2^261161165143 is an apocalyptic number.

261161165143 is a deficient number, since it is larger than the sum of its proper divisors (15362421497).

261161165143 is a wasteful number, since it uses less digits than its factorization.

261161165143 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15362421496.

The product of its digits is 25920, while the sum is 37.

The spelling of 261161165143 in words is "two hundred sixty-one billion, one hundred sixty-one million, one hundred sixty-five thousand, one hundred forty-three".