6918987 has 4 divisors (see below), whose sum is σ = 9225320. Its totient is φ = 4612656.

The previous prime is 6918979. The next prime is 6918997. The reversal of 6918987 is 7898196.

It is a happy number.

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

It is not a de Polignac number, because 6918987 - 2³ = 6918979 is a prime.

It is a super-2 number, since 2×6918987² = 95744762212338, which contains 22 as substring.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6918997) 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, 1153162 + ... + 1153167.

It is an arithmetic number, because the mean of its divisors is an integer number (2306330).

Almost surely, 2^6918987 is an apocalyptic number.

6918987 is a deficient number, since it is larger than the sum of its proper divisors (2306333).

6918987 is a wasteful number, since it uses less digits than its factorization.

6918987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2306332.

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

The square root of 6918987 is about 2630.3967381367. The cubic root of 6918987 is about 190.5522896394.

The spelling of 6918987 in words is "six million, nine hundred eighteen thousand, nine hundred eighty-seven".