1158781321 has 2 divisors, whose sum is σ = 1158781322. Its totient is φ = 1158781320.

The previous prime is 1158781301. The next prime is 1158781339. The reversal of 1158781321 is 1231878511.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1027907721 + 130873600 = 32061^2 + 11440^2 .

It is an emirp because it is prime and its reverse (1231878511) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1158781321 - 2¹⁹ = 1158257033 is a prime.

It is not a weakly prime, because it can be changed into another prime (1158781301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 579390660 + 579390661.

It is an arithmetic number, because the mean of its divisors is an integer number (579390661).

Almost surely, 2^1158781321 is an apocalyptic number.

It is an amenable number.

1158781321 is a deficient number, since it is larger than the sum of its proper divisors (1).

1158781321 is an equidigital number, since it uses as much as digits as its factorization.

1158781321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13440, while the sum is 37.

The square root of 1158781321 is about 34040.8772066761. The cubic root of 1158781321 is about 1050.3494894051.

The spelling of 1158781321 in words is "one billion, one hundred fifty-eight million, seven hundred eighty-one thousand, three hundred twenty-one".