6451440 has 40 divisors (see below), whose sum is σ = 20000208. Its totient is φ = 1720320.

The previous prime is 6451439. The next prime is 6451451. The reversal of 6451440 is 441546.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 6451440.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13201 + ... + 13680.

Almost surely, 2^6451440 is an apocalyptic number.

6451440 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

6451440 is an abundant number, since it is smaller than the sum of its proper divisors (13548768).

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

6451440 is a wasteful number, since it uses less digits than its factorization.

6451440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26897 (or 26891 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 24.

The square root of 6451440 is about 2539.9685037417. The cubic root of 6451440 is about 186.1596501862.

Adding to 6451440 its reverse (441546), we get a palindrome (6892986).

The spelling of 6451440 in words is "six million, four hundred fifty-one thousand, four hundred forty".