1181365641 has 63 divisors (see below), whose sum is σ = 1897685181. Its totient is φ = 734989464.

The previous prime is 1181365609. The next prime is 1181365681. The reversal of 1181365641 is 1465631811.

It is a happy number.

The square root of 1181365641 is 34371.

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

1181365641 is a `hidden beast` number, since 1 + 1 + 8 + 1 + 3 + 6 + 5 + 641 = 666.

It is not a de Polignac number, because 1181365641 - 2⁵ = 1181365609 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1181365596 and 1181365605.

It is not an unprimeable number, because it can be changed into a prime (1181365681) by changing a digit.

It is a polite number, since it can be written in 62 ways as a sum of consecutive naturals, for example, 17632290 + ... + 17632356.

It is an arithmetic number, because the mean of its divisors is an integer number (30121987).

Almost surely, 2^1181365641 is an apocalyptic number.

1181365641 is the 34371-st square number.

1181365641 is the 17186-th centered octagonal number.

It is an amenable number.

1181365641 is a deficient number, since it is larger than the sum of its proper divisors (716319540).

1181365641 is an frugal number, since it uses more digits than its factorization.

1181365641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 190 (or 89 counting only the distinct ones).

The product of its digits is 17280, while the sum is 36.

The cubic root of 1181365641 is about 1057.1293042047.

Multiplying 1181365641 by its sum of digits (36), we get a square (42529163076 = 206226²).

The spelling of 1181365641 in words is "one billion, one hundred eighty-one million, three hundred sixty-five thousand, six hundred forty-one".