1161523213 has 4 divisors (see below), whose sum is σ = 1163670748. Its totient is φ = 1159375680.

The previous prime is 1161523201. The next prime is 1161523217. The reversal of 1161523213 is 3123251611.

It is a happy number.

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 173238244 + 988284969 = 13162^2 + 31437^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1161523213 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1161523217) 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, 1072956 + ... + 1074037.

It is an arithmetic number, because the mean of its divisors is an integer number (290917687).

Almost surely, 2^1161523213 is an apocalyptic number.

It is an amenable number.

1161523213 is a deficient number, since it is larger than the sum of its proper divisors (2147535).

1161523213 is an equidigital number, since it uses as much as digits as its factorization.

1161523213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2147534.

The product of its digits is 1080, while the sum is 25.

The square root of 1161523213 is about 34081.1269326588. The cubic root of 1161523213 is about 1051.1772775582.

Adding to 1161523213 its reverse (3123251611), we get a palindrome (4284774824).

The spelling of 1161523213 in words is "one billion, one hundred sixty-one million, five hundred twenty-three thousand, two hundred thirteen".