6999643 has 16 divisors (see below), whose sum is σ = 8487360. Its totient is φ = 5651520.

The previous prime is 6999611. The next prime is 6999647. The reversal of 6999643 is 3469996.

It is not a de Polignac number, because 6999643 - 2⁵ = 6999611 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 6999593 and 6999602.

It is not an unprimeable number, because it can be changed into a prime (6999647) 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, 170703 + ... + 170743.

It is an arithmetic number, because the mean of its divisors is an integer number (530460).

Almost surely, 2^6999643 is an apocalyptic number.

6999643 is a deficient number, since it is larger than the sum of its proper divisors (1487717).

6999643 is an frugal number, since it uses more digits than its factorization.

With its predecessor (6999642) it forms a Ruth-Aaron pair, since the sum of their distinct prime factors is the same (77).

6999643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135 (or 77 counting only the distinct ones).

The product of its digits is 314928, while the sum is 46.

The square root of 6999643 is about 2645.6838435459. The cubic root of 6999643 is about 191.2898662389.

The spelling of 6999643 in words is "six million, nine hundred ninety-nine thousand, six hundred forty-three".