1155266871661 has 16 divisors (see below), whose sum is σ = 1328022169344. Its totient is φ = 984454015104.

The previous prime is 1155266871641. The next prime is 1155266871721. The reversal of 1155266871661 is 1661786625511.

It is not a de Polignac number, because 1155266871661 - 2³⁹ = 605511057773 is a prime.

It is a super-3 number, since 3×1155266871661³ (a number of 37 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1155266871601) 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, 507871 + ... + 1602643.

It is an arithmetic number, because the mean of its divisors is an integer number (83001385584).

Almost surely, 2^{1155266871661} is an apocalyptic number.

It is an amenable number.

1155266871661 is a deficient number, since it is larger than the sum of its proper divisors (172755297683).

1155266871661 is a wasteful number, since it uses less digits than its factorization.

1155266871661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1095660.

The product of its digits is 3628800, while the sum is 55.

The spelling of 1155266871661 in words is "one trillion, one hundred fifty-five billion, two hundred sixty-six million, eight hundred seventy-one thousand, six hundred sixty-one".