100805261261 has 2 divisors, whose sum is σ = 100805261262. Its totient is φ = 100805261260.

The previous prime is 100805261257. The next prime is 100805261317. The reversal of 100805261261 is 162162508001.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 74908405636 + 25896855625 = 273694^2 + 160925^2 .

It is a cyclic number.

It is not a de Polignac number, because 100805261261 - 2² = 100805261257 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (100805201261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50402630630 + 50402630631.

It is an arithmetic number, because the mean of its divisors is an integer number (50402630631).

Almost surely, 2^100805261261 is an apocalyptic number.

It is an amenable number.

100805261261 is a deficient number, since it is larger than the sum of its proper divisors (1).

100805261261 is an equidigital number, since it uses as much as digits as its factorization.

100805261261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5760, while the sum is 32.

Adding to 100805261261 its reverse (162162508001), we get a palindrome (262967769262).

The spelling of 100805261261 in words is "one hundred billion, eight hundred five million, two hundred sixty-one thousand, two hundred sixty-one".