1321091121 has 16 divisors (see below), whose sum is σ = 2017649664. Its totient is φ = 753199824.

The previous prime is 1321091119. The next prime is 1321091141. The reversal of 1321091121 is 1211901231.

It is a happy number.

It is not a de Polignac number, because 1321091121 - 2¹ = 1321091119 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is not an unprimeable number, because it can be changed into a prime (1321091141) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 61701 + ... + 80306.

It is an arithmetic number, because the mean of its divisors is an integer number (126103104).

Almost surely, 2^1321091121 is an apocalyptic number.

It is an amenable number.

1321091121 is a deficient number, since it is larger than the sum of its proper divisors (696558543).

1321091121 is a wasteful number, since it uses less digits than its factorization.

1321091121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142460.

The product of its (nonzero) digits is 108, while the sum is 21.

The square root of 1321091121 is about 36346.8172059123. The cubic root of 1321091121 is about 1097.2634791431.

Adding to 1321091121 its reverse (1211901231), we get a palindrome (2532992352).

The spelling of 1321091121 in words is "one billion, three hundred twenty-one million, ninety-one thousand, one hundred twenty-one".