1261226611 has 4 divisors (see below), whose sum is σ = 1261485400. Its totient is φ = 1260967824.

The previous prime is 1261226609. The next prime is 1261226627. The reversal of 1261226611 is 1166221621.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1261226611 - 2¹ = 1261226609 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1261226611.

It is not an unprimeable number, because it can be changed into a prime (1261226641) 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, 121941 + ... + 131878.

It is an arithmetic number, because the mean of its divisors is an integer number (315371350).

Almost surely, 2^1261226611 is an apocalyptic number.

1261226611 is a deficient number, since it is larger than the sum of its proper divisors (258789).

1261226611 is an equidigital number, since it uses as much as digits as its factorization.

1261226611 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 258788.

The product of its digits is 1728, while the sum is 28.

The square root of 1261226611 is about 35513.7524207172. The cubic root of 1261226611 is about 1080.4326715752.

The spelling of 1261226611 in words is "one billion, two hundred sixty-one million, two hundred twenty-six thousand, six hundred eleven".