1321119991 has 2 divisors, whose sum is σ = 1321119992. Its totient is φ = 1321119990.

The previous prime is 1321119979. The next prime is 1321120001. The reversal of 1321119991 is 1999111231.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1321119991 - 2¹⁵ = 1321087223 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1321119991.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1321119941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660559995 + 660559996.

It is an arithmetic number, because the mean of its divisors is an integer number (660559996).

Almost surely, 2^1321119991 is an apocalyptic number.

1321119991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1321119991 is an equidigital number, since it uses as much as digits as its factorization.

1321119991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4374, while the sum is 37.

The square root of 1321119991 is about 36347.2143499333. The cubic root of 1321119991 is about 1097.2714719720.

The spelling of 1321119991 in words is "one billion, three hundred twenty-one million, one hundred nineteen thousand, nine hundred ninety-one".