1921378337 has 2 divisors, whose sum is σ = 1921378338. Its totient is φ = 1921378336.

The previous prime is 1921378321. The next prime is 1921378397. The reversal of 1921378337 is 7338731291.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1798523281 + 122855056 = 42409^2 + 11084^2 .

It is a cyclic number.

It is not a de Polignac number, because 1921378337 - 2⁴ = 1921378321 is a prime.

It is not a weakly prime, because it can be changed into another prime (1921378397) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 960689168 + 960689169.

It is an arithmetic number, because the mean of its divisors is an integer number (960689169).

Almost surely, 2^1921378337 is an apocalyptic number.

It is an amenable number.

1921378337 is a deficient number, since it is larger than the sum of its proper divisors (1).

1921378337 is an equidigital number, since it uses as much as digits as its factorization.

1921378337 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 190512, while the sum is 44.

The square root of 1921378337 is about 43833.5298259221. The cubic root of 1921378337 is about 1243.1903488458.

The spelling of 1921378337 in words is "one billion, nine hundred twenty-one million, three hundred seventy-eight thousand, three hundred thirty-seven".