1291337221 has 8 divisors (see below), whose sum is σ = 1375204824. Its totient is φ = 1208348160.

The previous prime is 1291337197. The next prime is 1291337227. The reversal of 1291337221 is 1227331921.

It can be written as a sum of positive squares in 4 ways, for example, as 1008761121 + 282576100 = 31761^2 + 16810^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1291337221 - 2¹⁷ = 1291206149 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 (1291337227) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 216600 + ... + 222481.

It is an arithmetic number, because the mean of its divisors is an integer number (171900603).

Almost surely, 2^1291337221 is an apocalyptic number.

It is an amenable number.

1291337221 is a deficient number, since it is larger than the sum of its proper divisors (83867603).

1291337221 is a wasteful number, since it uses less digits than its factorization.

1291337221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 439271.

The product of its digits is 4536, while the sum is 31.

The square root of 1291337221 is about 35935.1808260373. The cubic root of 1291337221 is about 1088.9632487008.

The spelling of 1291337221 in words is "one billion, two hundred ninety-one million, three hundred thirty-seven thousand, two hundred twenty-one".