1999887 has 16 divisors (see below), whose sum is σ = 2808960. Its totient is φ = 1264032.

The previous prime is 1999871. The next prime is 1999889. The reversal of 1999887 is 7889991.

It is not a de Polignac number, because 1999887 - 2⁴ = 1999871 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1999889) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4564 + ... + 4982.

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

2^1999887 is an apocalyptic number.

1999887 is a deficient number, since it is larger than the sum of its proper divisors (809073).

1999887 is a wasteful number, since it uses less digits than its factorization.

1999887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 502.

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

The square root of 1999887 is about 1414.1736102756. The cubic root of 1999887 is about 125.9897320935.

The spelling of 1999887 in words is "one million, nine hundred ninety-nine thousand, eight hundred eighty-seven".