1266117187361 has 4 divisors (see below), whose sum is σ = 1363510817172. Its totient is φ = 1168723557552.

The previous prime is 1266117187297. The next prime is 1266117187399. The reversal of 1266117187361 is 1637817116621.

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

It can be written as a sum of positive squares in 2 ways, for example, as 723418291600 + 542698895761 = 850540^2 + 736681^2 .

It is a cyclic number.

It is not a de Polignac number, because 1266117187361 - 2⁶ = 1266117187297 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1266117187961) 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, 48696814886 + ... + 48696814911.

It is an arithmetic number, because the mean of its divisors is an integer number (340877704293).

Almost surely, 2^{1266117187361} is an apocalyptic number.

It is an amenable number.

1266117187361 is a deficient number, since it is larger than the sum of its proper divisors (97393629811).

1266117187361 is an equidigital number, since it uses as much as digits as its factorization.

1266117187361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97393629810.

The product of its digits is 508032, while the sum is 50.

The spelling of 1266117187361 in words is "one trillion, two hundred sixty-six billion, one hundred seventeen million, one hundred eighty-seven thousand, three hundred sixty-one".