6407640 has 128 divisors (see below), whose sum is σ = 22680000. Its totient is φ = 1603584.

The previous prime is 6407591. The next prime is 6407671. The reversal of 6407640 is 467046.

It is a Harshad number since it is a multiple of its sum of digits (27).

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 31 ways as a sum of consecutive naturals, for example, 18186 + ... + 18534.

Almost surely, 2^6407640 is an apocalyptic number.

6407640 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 6407640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11340000).

6407640 is an abundant number, since it is smaller than the sum of its proper divisors (16272360).

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

6407640 is a wasteful number, since it uses less digits than its factorization.

6407640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 386 (or 376 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 27.

The square root of 6407640 is about 2531.3316653493. The cubic root of 6407640 is about 185.7374025887.

The spelling of 6407640 in words is "six million, four hundred seven thousand, six hundred forty".