7640640 has 168 divisors, whose sum is σ = 30114240. Its totient is φ = 1741824.

The previous prime is 7640621. The next prime is 7640681. The reversal of 7640640 is 460467.

It is a tau number, because it is divible by the number of its divisors (168).

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, 19971 + ... + 20349.

Almost surely, 2^7640640 is an apocalyptic number.

7640640 is a gapful number since it is divisible by the number (70) 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 7640640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15057120).

7640640 is an abundant number, since it is smaller than the sum of its proper divisors (22473600).

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

7640640 is a wasteful number, since it uses less digits than its factorization.

7640640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 409 (or 396 counting only the distinct ones).

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

The square root of 7640640 is about 2764.1707617295. The cubic root of 7640640 is about 196.9593395259.

The spelling of 7640640 in words is "seven million, six hundred forty thousand, six hundred forty".