6899940 has 36 divisors (see below), whose sum is σ = 20930364. Its totient is φ = 1839936.

The previous prime is 6899923. The next prime is 6899947. The reversal of 6899940 is 499986.

6899940 = 60² + 61² + ... + 275².

It can be written as a sum of positive squares in 2 ways, for example, as 3594816 + 3305124 = 1896^2 + 1818^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6899947) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18987 + ... + 19346.

It is an arithmetic number, because the mean of its divisors is an integer number (581399).

Almost surely, 2^6899940 is an apocalyptic number.

6899940 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

6899940 is an abundant number, since it is smaller than the sum of its proper divisors (14030424).

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

6899940 is a wasteful number, since it uses less digits than its factorization.

6899940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38348 (or 38343 counting only the distinct ones).

The product of its (nonzero) digits is 139968, while the sum is 45.

The square root of 6899940 is about 2626.7736864831. The cubic root of 6899940 is about 190.3772743749.

The spelling of 6899940 in words is "six million, eight hundred ninety-nine thousand, nine hundred forty".