6987891 has 16 divisors (see below), whose sum is σ = 9642240. Its totient is φ = 4499040.

The previous prime is 6987863. The next prime is 6987907. The reversal of 6987891 is 1987896.

It is a happy number.

It is not a de Polignac number, because 6987891 - 2¹³ = 6979699 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 6987891.

It is not an unprimeable number, because it can be changed into a prime (6987821) 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, 10980 + ... + 11598.

It is an arithmetic number, because the mean of its divisors is an integer number (602640).

Almost surely, 2^6987891 is an apocalyptic number.

6987891 is a deficient number, since it is larger than the sum of its proper divisors (2654349).

6987891 is a wasteful number, since it uses less digits than its factorization.

6987891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 746.

The product of its digits is 217728, while the sum is 48.

The square root of 6987891 is about 2643.4619346607. The cubic root of 6987891 is about 191.1827513574.

The spelling of 6987891 in words is "six million, nine hundred eighty-seven thousand, eight hundred ninety-one".