1997889 has 16 divisors (see below), whose sum is σ = 2808960. Its totient is φ = 1261440.

The previous prime is 1997887. The next prime is 1997899. The reversal of 1997889 is 9887991.

It is not a de Polignac number, because 1997889 - 2¹ = 1997887 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1997887) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4332 + ... + 4770.

It is an arithmetic number, because the mean of its divisors is an integer number (175560).

2^1997889 is an apocalyptic number.

It is an amenable number.

1997889 is a deficient number, since it is larger than the sum of its proper divisors (811071).

1997889 is a wasteful number, since it uses less digits than its factorization.

1997889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 520.

The product of its digits is 326592, while the sum is 51.

The square root of 1997889 is about 1413.4670141181. The cubic root of 1997889 is about 125.9477611619.

The spelling of 1997889 in words is "one million, nine hundred ninety-seven thousand, eight hundred eighty-nine".