6691440 has 120 divisors (see below), whose sum is σ = 24172560. Its totient is φ = 1526784.

The previous prime is 6691427. The next prime is 6691457. The reversal of 6691440 is 441966.

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

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 6691398 and 6691407.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11476 + ... + 12044.

It is an arithmetic number, because the mean of its divisors is an integer number (201438).

Almost surely, 2^6691440 is an apocalyptic number.

6691440 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 6691440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12086280).

6691440 is an abundant number, since it is smaller than the sum of its proper divisors (17481120).

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

6691440 is a wasteful number, since it uses less digits than its factorization.

6691440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 599 (or 586 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 30.

The square root of 6691440 is about 2586.7817843800. The cubic root of 6691440 is about 188.4400435977.

It can be divided in two parts, 6 and 691440, that multiplied together give a triangular number (4148640 = T₂₈₈₀).

The spelling of 6691440 in words is "six million, six hundred ninety-one thousand, four hundred forty".