1161406381 has 4 divisors (see below), whose sum is σ = 1162337500. Its totient is φ = 1160475264.

The previous prime is 1161406361. The next prime is 1161406397. The reversal of 1161406381 is 1836041611.

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 903964356 + 257442025 = 30066^2 + 16045^2 .

It is a cyclic number.

It is not a de Polignac number, because 1161406381 - 2⁵ = 1161406349 is a prime.

It is a super-2 number, since 2×1161406381² = 2697729563655034322, which contains 22 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 (1161406361) 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 3 ways as a sum of consecutive naturals, for example, 463686 + ... + 466183.

It is an arithmetic number, because the mean of its divisors is an integer number (290584375).

Almost surely, 2^1161406381 is an apocalyptic number.

It is an amenable number.

1161406381 is a deficient number, since it is larger than the sum of its proper divisors (931119).

1161406381 is an equidigital number, since it uses as much as digits as its factorization.

1161406381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 931118.

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 1161406381 is about 34079.4128617264. The cubic root of 1161406381 is about 1051.1420320977.

Adding to 1161406381 its reverse (1836041611), we get a palindrome (2997447992).

The spelling of 1161406381 in words is "one billion, one hundred sixty-one million, four hundred six thousand, three hundred eighty-one".