1327691921 has 2 divisors, whose sum is σ = 1327691922. Its totient is φ = 1327691920.

The previous prime is 1327691837. The next prime is 1327691929. The reversal of 1327691921 is 1291967231.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1322122321 + 5569600 = 36361^2 + 2360^2 .

It is a cyclic number.

It is not a de Polignac number, because 1327691921 - 2¹⁸ = 1327429777 is a prime.

It is not a weakly prime, because it can be changed into another prime (1327691929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 663845960 + 663845961.

It is an arithmetic number, because the mean of its divisors is an integer number (663845961).

Almost surely, 2^1327691921 is an apocalyptic number.

It is an amenable number.

1327691921 is a deficient number, since it is larger than the sum of its proper divisors (1).

1327691921 is an equidigital number, since it uses as much as digits as its factorization.

1327691921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 40824, while the sum is 41.

The square root of 1327691921 is about 36437.5070634642. The cubic root of 1327691921 is about 1099.0879274288.

The spelling of 1327691921 in words is "one billion, three hundred twenty-seven million, six hundred ninety-one thousand, nine hundred twenty-one".