7920640 has 176 divisors, whose sum is σ = 24760512. Its totient is φ = 2359296.

The previous prime is 7920629. The next prime is 7920641. The reversal of 7920640 is 460297.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a junction number, because it is equal to n+sod(n) for n = 7920599 and 7920608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7920641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 465912 + ... + 465928.

Almost surely, 2^7920640 is an apocalyptic number.

7920640 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 7920640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12380256).

7920640 is an abundant number, since it is smaller than the sum of its proper divisors (16839872).

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

7920640 is a wasteful number, since it uses less digits than its factorization.

7920640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62 (or 44 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 28.

The square root of 7920640 is about 2814.3631606458. The cubic root of 7920640 is about 199.3364677257.

The spelling of 7920640 in words is "seven million, nine hundred twenty thousand, six hundred forty".