1265934934991 has 4 divisors (see below), whose sum is σ = 1266205496400. Its totient is φ = 1265664373584.

The previous prime is 1265934934973. The next prime is 1265934934993. The reversal of 1265934934991 is 1994394395621.

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 1265934934991 - 2¹⁴ = 1265934918607 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 (1265934934993) 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, 135273686 + ... + 135283043.

It is an arithmetic number, because the mean of its divisors is an integer number (316551374100).

Almost surely, 2^{1265934934991} is an apocalyptic number.

1265934934991 is a deficient number, since it is larger than the sum of its proper divisors (270561409).

1265934934991 is an equidigital number, since it uses as much as digits as its factorization.

1265934934991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 270561408.

The product of its digits is 56687040, while the sum is 65.

The spelling of 1265934934991 in words is "one trillion, two hundred sixty-five billion, nine hundred thirty-four million, nine hundred thirty-four thousand, nine hundred ninety-one".