6987691 has 4 divisors (see below), whose sum is σ = 6993112. Its totient is φ = 6982272.

The previous prime is 6987683. The next prime is 6987703. The reversal of 6987691 is 1967896.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 6987691 - 2³ = 6987683 is a prime.

It is a super-2 number, since 2×6987691² = 97655651022962, which contains 22 as substring.

It is a Duffinian number.

6987691 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (6987601) 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, 460 + ... + 3766.

It is an arithmetic number, because the mean of its divisors is an integer number (1748278).

Almost surely, 2^6987691 is an apocalyptic number.

6987691 is a deficient number, since it is larger than the sum of its proper divisors (5421).

6987691 is a wasteful number, since it uses less digits than its factorization.

6987691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5420.

The product of its digits is 163296, while the sum is 46.

The square root of 6987691 is about 2643.4241052090. The cubic root of 6987691 is about 191.1809273967.

The spelling of 6987691 in words is "six million, nine hundred eighty-seven thousand, six hundred ninety-one".