1888991 has 4 divisors (see below), whose sum is σ = 2034312. Its totient is φ = 1743672.

The previous prime is 1888981. The next prime is 1889009. The reversal of 1888991 is 1998881.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1888991 - 2⁶ = 1888927 is a prime.

It is a Duffinian number.

It is a zygodrome in base 12.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1888981) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 72641 + ... + 72666.

It is an arithmetic number, because the mean of its divisors is an integer number (508578).

2^1888991 is an apocalyptic number.

1888991 is a deficient number, since it is larger than the sum of its proper divisors (145321).

1888991 is a wasteful number, since it uses less digits than its factorization.

1888991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 145320.

The product of its digits is 41472, while the sum is 44.

The square root of 1888991 is about 1374.4056897438. The cubic root of 1888991 is about 123.6165530837.

The spelling of 1888991 in words is "one million, eight hundred eighty-eight thousand, nine hundred ninety-one".