91855758707881 has 81 divisors (see below), whose sum is σ = 116270979946821. Its totient is φ = 72340176190464.

The previous prime is 91855758707837. The next prime is 91855758707891. The reversal of 91855758707881 is 18870785755819.

The square root of 91855758707881 is 9584141.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 9442769722281 + 82412988985600 = 3072909^2 + 9078160^2 .

It is not a de Polignac number, because 91855758707881 - 2¹⁹ = 91855758183593 is a prime.

It is a super-2 number, since 2×91855758707881² (a number of 29 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (91855758707891) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 49042048561 + ... + 49042050433.

Almost surely, 2^{91855758707881} is an apocalyptic number.

91855758707881 is the 9584141-st square number.

91855758707881 is the 4792071-st centered octagonal number.

It is an amenable number.

91855758707881 is a deficient number, since it is larger than the sum of its proper divisors (24415221238940).

91855758707881 is an frugal number, since it uses more digits than its factorization.

91855758707881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3880 (or 1940 counting only the distinct ones).

The product of its (nonzero) digits is 1580544000, while the sum is 79.

The spelling of 91855758707881 in words is "ninety-one trillion, eight hundred fifty-five billion, seven hundred fifty-eight million, seven hundred seven thousand, eight hundred eighty-one".