618881161 has 4 divisors (see below), whose sum is σ = 618969492. Its totient is φ = 618792832.

The previous prime is 618881147. The next prime is 618881191. The reversal of 618881161 is 161188816.

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 554319936 + 64561225 = 23544^2 + 8035^2 .

It is a cyclic number.

It is not a de Polignac number, because 618881161 - 2¹⁷ = 618750089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (618881191) 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, 32656 + ... + 48001.

It is an arithmetic number, because the mean of its divisors is an integer number (154742373).

Almost surely, 2^618881161 is an apocalyptic number.

It is an amenable number.

618881161 is a deficient number, since it is larger than the sum of its proper divisors (88331).

618881161 is an equidigital number, since it uses as much as digits as its factorization.

618881161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88330.

The product of its digits is 18432, while the sum is 40.

The square root of 618881161 is about 24877.3222232619. The cubic root of 618881161 is about 852.1886668265.

The spelling of 618881161 in words is "six hundred eighteen million, eight hundred eighty-one thousand, one hundred sixty-one".