6861989 has 4 divisors (see below), whose sum is σ = 6939180. Its totient is φ = 6784800.

The previous prime is 6861977. The next prime is 6861997. The reversal of 6861989 is 9891686.

6861989 = 101² + 102² + ... + 278².

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

It can be written as a sum of positive squares in 2 ways, for example, as 3869089 + 2992900 = 1967^2 + 1730^2 .

It is a cyclic number.

It is not a de Polignac number, because 6861989 - 2⁴ = 6861973 is a prime.

It is a super-2 number, since 2×6861989² = 94173786072242, which contains 22 as substring.

6861989 is a strobogrammatic number because it is the same when read upside-down.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6861949) 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 3 ways as a sum of consecutive naturals, for example, 38462 + ... + 38639.

It is an arithmetic number, because the mean of its divisors is an integer number (1734795).

Almost surely, 2^6861989 is an apocalyptic number.

It is an amenable number.

6861989 is a deficient number, since it is larger than the sum of its proper divisors (77191).

6861989 is an equidigital number, since it uses as much as digits as its factorization.

6861989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77190.

The product of its digits is 186624, while the sum is 47.

The square root of 6861989 is about 2619.5398450873. The cubic root of 6861989 is about 190.0275952532.

The spelling of 6861989 in words is "six million, eight hundred sixty-one thousand, nine hundred eighty-nine".