1921808107 has 2 divisors, whose sum is σ = 1921808108. Its totient is φ = 1921808106.

The previous prime is 1921808089. The next prime is 1921808123. The reversal of 1921808107 is 7018081291.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1921808107 - 2²⁷ = 1787590379 is a prime.

It is not a weakly prime, because it can be changed into another prime (1921808137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 960904053 + 960904054.

It is an arithmetic number, because the mean of its divisors is an integer number (960904054).

Almost surely, 2^1921808107 is an apocalyptic number.

1921808107 is a deficient number, since it is larger than the sum of its proper divisors (1).

1921808107 is an equidigital number, since it uses as much as digits as its factorization.

1921808107 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8064, while the sum is 37.

The square root of 1921808107 is about 43838.4318492348. The cubic root of 1921808107 is about 1243.2830333655.

Adding to 1921808107 its reverse (7018081291), we get a palindrome (8939889398).

The spelling of 1921808107 in words is "one billion, nine hundred twenty-one million, eight hundred eight thousand, one hundred seven".