1921919 has 2 divisors, whose sum is σ = 1921920. Its totient is φ = 1921918.

The previous prime is 1921889. The next prime is 1921921. The reversal of 1921919 is 9191291.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1921919 - 2²⁰ = 873343 is a prime.

It is a super-2 number, since 2×1921919² = 7387545285122, which contains 22 as substring.

Together with 1921921, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1921319) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 960959 + 960960.

It is an arithmetic number, because the mean of its divisors is an integer number (960960).

2^1921919 is an apocalyptic number.

1921919 is a deficient number, since it is larger than the sum of its proper divisors (1).

1921919 is an equidigital number, since it uses as much as digits as its factorization.

1921919 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1458, while the sum is 32.

The square root of 1921919 is about 1386.3329325959. The cubic root of 1921919 is about 124.3306946390.

The spelling of 1921919 in words is "one million, nine hundred twenty-one thousand, nine hundred nineteen".