1871989 has 8 divisors (see below), whose sum is σ = 2265408. Its totient is φ = 1510080.

The previous prime is 1871983. The next prime is 1872001. The reversal of 1871989 is 9891781.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1871989 - 2³ = 1871981 is a prime.

It is a super-2 number, since 2×1871989² = 7008685632242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1871981) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7747 + ... + 7984.

It is an arithmetic number, because the mean of its divisors is an integer number (283176).

2^1871989 is an apocalyptic number.

It is an amenable number.

1871989 is a deficient number, since it is larger than the sum of its proper divisors (393419).

1871989 is a wasteful number, since it uses less digits than its factorization.

1871989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15755.

The product of its digits is 36288, while the sum is 43.

The square root of 1871989 is about 1368.2064902638. The cubic root of 1871989 is about 123.2445615562.

The spelling of 1871989 in words is "one million, eight hundred seventy-one thousand, nine hundred eighty-nine".