261208858281 has 16 divisors (see below), whose sum is σ = 401752479744. Its totient is φ = 147867229584.

The previous prime is 261208858259. The next prime is 261208858363. The reversal of 261208858281 is 182858802162.

It is a happy number.

It is not a de Polignac number, because 261208858281 - 2⁵ = 261208858249 is a prime.

It is a super-2 number, since 2×261208858281² (a number of 24 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (261208858081) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 58121665 + ... + 58126158.

It is an arithmetic number, because the mean of its divisors is an integer number (25109529984).

Almost surely, 2^261208858281 is an apocalyptic number.

261208858281 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

261208858281 is a deficient number, since it is larger than the sum of its proper divisors (140543621463).

261208858281 is a wasteful number, since it uses less digits than its factorization.

261208858281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116247940.

The product of its (nonzero) digits is 983040, while the sum is 51.

The spelling of 261208858281 in words is "two hundred sixty-one billion, two hundred eight million, eight hundred fifty-eight thousand, two hundred eighty-one".