1261106101 has 4 divisors (see below), whose sum is σ = 1264189900. Its totient is φ = 1258022304.

The previous prime is 1261106083. The next prime is 1261106117. The reversal of 1261106101 is 1016011621.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1016011621 = 101 ⋅10059521.

It can be written as a sum of positive squares in 2 ways, for example, as 1219825476 + 41280625 = 34926^2 + 6425^2 .

It is a cyclic number.

It is not a de Polignac number, because 1261106101 - 2¹⁹ = 1260581813 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261106141) 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, 1541286 + ... + 1542103.

It is an arithmetic number, because the mean of its divisors is an integer number (316047475).

Almost surely, 2^1261106101 is an apocalyptic number.

It is an amenable number.

1261106101 is a deficient number, since it is larger than the sum of its proper divisors (3083799).

1261106101 is an equidigital number, since it uses as much as digits as its factorization.

1261106101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3083798.

The product of its (nonzero) digits is 72, while the sum is 19.

The square root of 1261106101 is about 35512.0557135179. The cubic root of 1261106101 is about 1080.3982587564.

Adding to 1261106101 its reverse (1016011621), we get a palindrome (2277117722).

The spelling of 1261106101 in words is "one billion, two hundred sixty-one million, one hundred six thousand, one hundred one".