6998721 has 8 divisors (see below), whose sum is σ = 9384480. Its totient is φ = 4639392.

The previous prime is 6998711. The next prime is 6998737. The reversal of 6998721 is 1278996.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 6998721 - 2⁹ = 6998209 is a prime.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (6998711) 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 7 ways as a sum of consecutive naturals, for example, 5980 + ... + 7053.

It is an arithmetic number, because the mean of its divisors is an integer number (1173060).

Almost surely, 2^6998721 is an apocalyptic number.

It is an amenable number.

6998721 is a deficient number, since it is larger than the sum of its proper divisors (2385759).

6998721 is a wasteful number, since it uses less digits than its factorization.

6998721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13215.

The product of its digits is 54432, while the sum is 42.

The square root of 6998721 is about 2645.5095917422. The cubic root of 6998721 is about 191.2814669058.

It can be divided in two parts, 69 and 98721, that added together give a triangular number (98790 = T₄₄₄).

The spelling of 6998721 in words is "six million, nine hundred ninety-eight thousand, seven hundred twenty-one".