1165607881 has 3 divisors (see below), whose sum is σ = 1165642023. Its totient is φ = 1165573740.

The previous prime is 1165607857. The next prime is 1165607887. The reversal of 1165607881 is 1887065611.

The square root of 1165607881 is 34141.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 592484281 + 573123600 = 24341^2 + 23940^2 .

It is not a de Polignac number, because 1165607881 - 2⁷ = 1165607753 is a prime.

It is a super-2 number, since 2×1165607881² = 2717283464498620322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1165607887) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 17071 + ... + 51211.

It is an arithmetic number, because the mean of its divisors is an integer number (388547341).

Almost surely, 2^1165607881 is an apocalyptic number.

1165607881 is the 34141-st square number.

1165607881 is the 17071-st centered octagonal number.

It is an amenable number.

1165607881 is a deficient number, since it is larger than the sum of its proper divisors (34142).

1165607881 is an frugal number, since it uses more digits than its factorization.

1165607881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68282 (or 34141 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 43.

The cubic root of 1165607881 is about 1052.4080426991.

The spelling of 1165607881 in words is "one billion, one hundred sixty-five million, six hundred seven thousand, eight hundred eighty-one".