1161320381 has 8 divisors (see below), whose sum is σ = 1251062904. Its totient is φ = 1071636480.

The previous prime is 1161320353. The next prime is 1161320383. The reversal of 1161320381 is 1830231611.

It can be written as a sum of positive squares in 4 ways, for example, as 74563225 + 1086757156 = 8635^2 + 32966^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1161320381 - 2²² = 1157126077 is a prime.

It is a super-2 number, since 2×1161320381² = 2697330054651970322, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1161320381.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1161320383) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32021 + ... + 57861.

It is an arithmetic number, because the mean of its divisors is an integer number (156382863).

Almost surely, 2^1161320381 is an apocalyptic number.

It is an amenable number.

1161320381 is a deficient number, since it is larger than the sum of its proper divisors (89742523).

1161320381 is a wasteful number, since it uses less digits than its factorization.

1161320381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29311.

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 1161320381 is about 34078.1510795407. The cubic root of 1161320381 is about 1051.1160864144.

Adding to 1161320381 its reverse (1830231611), we get a palindrome (2991551992).

The spelling of 1161320381 in words is "one billion, one hundred sixty-one million, three hundred twenty thousand, three hundred eighty-one".