6998640 has 120 divisors (see below), whose sum is σ = 23946384. Its totient is φ = 1689600.

The previous prime is 6998627. The next prime is 6998681. The reversal of 6998640 is 468996.

It is a tau number, because it is divible by the number of its divisors (120).

It is an Ulam number.

It is a d-powerful number, because it can be written as 6 + 9⁶ + 9⁷ + 8³ + 6⁸ + 4⁶ + 0 .

It is a junction number, because it is equal to n+sod(n) for n = 6998592 and 6998601.

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 28920 + ... + 29160.

Almost surely, 2^6998640 is an apocalyptic number.

6998640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6998640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11973192).

6998640 is an abundant number, since it is smaller than the sum of its proper divisors (16947744).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6998640 is a wasteful number, since it uses less digits than its factorization.

6998640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 279 (or 262 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 42.

The square root of 6998640 is about 2645.4942827381. The cubic root of 6998640 is about 191.2807289681.

It can be divided in two parts, 699 and 8640, that added together give a palindrome (9339).

The spelling of 6998640 in words is "six million, nine hundred ninety-eight thousand, six hundred forty".