1161331021 has 6 divisors (see below), whose sum is σ = 1200002766. Its totient is φ = 1123867800.

The previous prime is 1161331001. The next prime is 1161331049. The reversal of 1161331021 is 1201331611.

It can be written as a sum of positive squares in only one way, i.e., 822255625 + 339075396 = 28675^2 + 18414^2 .

It is not a de Polignac number, because 1161331021 - 2⁷ = 1161330893 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1161331021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1161331001) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 603270 + ... + 605191.

It is an arithmetic number, because the mean of its divisors is an integer number (200000461).

Almost surely, 2^1161331021 is an apocalyptic number.

It is an amenable number.

1161331021 is a deficient number, since it is larger than the sum of its proper divisors (38671745).

1161331021 is an equidigital number, since it uses as much as digits as its factorization.

1161331021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1208523 (or 1208492 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 19.

The square root of 1161331021 is about 34078.3071909389. The cubic root of 1161331021 is about 1051.1192965079.

Adding to 1161331021 its reverse (1201331611), we get a palindrome (2362662632).

The spelling of 1161331021 in words is "one billion, one hundred sixty-one million, three hundred thirty-one thousand, twenty-one".