261646136575031 has 4 divisors (see below), whose sum is σ = 281772762465432. Its totient is φ = 241519510684632.

The previous prime is 261646136575013. The next prime is 261646136575039. The reversal of 261646136575031 is 130575631646162.

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 261646136575031 - 2¹⁰ = 261646136574007 is a prime.

It is a super-2 number, since 2×261646136575031² (a number of 30 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261646136575039) 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, 10063312945181 + ... + 10063312945206.

It is an arithmetic number, because the mean of its divisors is an integer number (70443190616358).

Almost surely, 2^{261646136575031} is an apocalyptic number.

261646136575031 is a deficient number, since it is larger than the sum of its proper divisors (20126625890401).

261646136575031 is a wasteful number, since it uses less digits than its factorization.

261646136575031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20126625890400.

The product of its (nonzero) digits is 16329600, while the sum is 56.

The spelling of 261646136575031 in words is "two hundred sixty-one trillion, six hundred forty-six billion, one hundred thirty-six million, five hundred seventy-five thousand, thirty-one".