1291054681665 has 192 divisors, whose sum is σ = 2668895404032. Its totient is φ = 564938841600.

The previous prime is 1291054681661. The next prime is 1291054681669. The reversal of 1291054681665 is 5661864501921.

It is a happy number.

1291054681665 is a `hidden beast` number, since 1 + 2 + 9 + 10 + 5 + 468 + 166 + 5 = 666.

It is an interprime number because it is at equal distance from previous prime (1291054681661) and next prime (1291054681669).

It is not a de Polignac number, because 1291054681665 - 2² = 1291054681661 is a prime.

It is a super-2 number, since 2×1291054681665² (a number of 25 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1291054681661) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 462576420 + ... + 462579210.

It is an arithmetic number, because the mean of its divisors is an integer number (13900496896).

Almost surely, 2^{1291054681665} is an apocalyptic number.

1291054681665 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1291054681665 is an abundant number, since it is smaller than the sum of its proper divisors (1377840722367).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1291054681665 is a wasteful number, since it uses less digits than its factorization.

1291054681665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3340 (or 3337 counting only the distinct ones).

The product of its (nonzero) digits is 3110400, while the sum is 54.

The spelling of 1291054681665 in words is "one trillion, two hundred ninety-one billion, fifty-four million, six hundred eighty-one thousand, six hundred sixty-five".