1911997 has 4 divisors (see below), whose sum is σ = 1915456. Its totient is φ = 1908540.

The previous prime is 1911991. The next prime is 1912019. The reversal of 1911997 is 7991191.

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 a cyclic number.

It is not a de Polignac number, because 1911997 - 2¹¹ = 1909949 is a prime.

It is a Duffinian number.

1911997 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1911991) 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, 693 + ... + 2074.

It is an arithmetic number, because the mean of its divisors is an integer number (478864).

2^1911997 is an apocalyptic number.

It is an amenable number.

1911997 is a deficient number, since it is larger than the sum of its proper divisors (3459).

1911997 is an equidigital number, since it uses as much as digits as its factorization.

1911997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3458.

The product of its digits is 5103, while the sum is 37.

The square root of 1911997 is about 1382.7497966010. The cubic root of 1911997 is about 124.1163709834.

The spelling of 1911997 in words is "one million, nine hundred eleven thousand, nine hundred ninety-seven".