261556664741031 has 32 divisors (see below), whose sum is σ = 384399100431360. Its totient is φ = 156873611312000.

The previous prime is 261556664740993. The next prime is 261556664741039. The reversal of 261556664741031 is 130147466655162.

It is a happy number.

It is not a de Polignac number, because 261556664741031 - 2⁶ = 261556664740967 is a prime.

It is a super-2 number, since 2×261556664741031² (a number of 30 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261556664741039) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12143616 + ... + 25895573.

It is an arithmetic number, because the mean of its divisors is an integer number (12012471888480).

Almost surely, 2^{261556664741031} is an apocalyptic number.

261556664741031 is a deficient number, since it is larger than the sum of its proper divisors (122842435690329).

261556664741031 is a wasteful number, since it uses less digits than its factorization.

261556664741031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38041367.

The product of its (nonzero) digits is 21772800, while the sum is 57.

The spelling of 261556664741031 in words is "two hundred sixty-one trillion, five hundred fifty-six billion, six hundred sixty-four million, seven hundred forty-one thousand, thirty-one".