1791921 has 4 divisors (see below), whose sum is σ = 2389232. Its totient is φ = 1194612.

The previous prime is 1791901. The next prime is 1791941. The reversal of 1791921 is 1291971.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (1791901) and next prime (1791941).

It is not a de Polignac number, because 1791921 - 2⁶ = 1791857 is a prime.

It is a D-number.

It is a Duffinian number.

It is a Curzon number.

1791921 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1791901) 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 in 3 ways as a sum of consecutive naturals, for example, 298651 + ... + 298656.

It is an arithmetic number, because the mean of its divisors is an integer number (597308).

2^1791921 is an apocalyptic number.

It is an amenable number.

1791921 is a deficient number, since it is larger than the sum of its proper divisors (597311).

1791921 is an equidigital number, since it uses as much as digits as its factorization.

1791921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 597310.

The product of its digits is 1134, while the sum is 30.

The square root of 1791921 is about 1338.6265349230. The cubic root of 1791921 is about 121.4617739490.

The spelling of 1791921 in words is "one million, seven hundred ninety-one thousand, nine hundred twenty-one".