1291241233261 has 16 divisors (see below), whose sum is σ = 1507644762624. Its totient is φ = 1082936634624.

The previous prime is 1291241233231. The next prime is 1291241233291. The reversal of 1291241233261 is 1623321421921.

It is an interprime number because it is at equal distance from previous prime (1291241233231) and next prime (1291241233291).

It is a cyclic number.

It is not a de Polignac number, because 1291241233261 - 2¹⁵ = 1291241200493 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1291241233261.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1291241233231) 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, 4605580 + ... + 4877893.

It is an arithmetic number, because the mean of its divisors is an integer number (94227797664).

Almost surely, 2^{1291241233261} is an apocalyptic number.

It is an amenable number.

1291241233261 is a deficient number, since it is larger than the sum of its proper divisors (216403529363).

1291241233261 is an equidigital number, since it uses as much as digits as its factorization.

1291241233261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9483900.

The product of its digits is 31104, while the sum is 37.

The spelling of 1291241233261 in words is "one trillion, two hundred ninety-one billion, two hundred forty-one million, two hundred thirty-three thousand, two hundred sixty-one".