7998640 has 40 divisors (see below), whose sum is σ = 20029968. Its totient is φ = 2952960.

The previous prime is 7998637. The next prime is 7998643. The reversal of 7998640 is 468997.

7998640 is nontrivially palindromic in base 15.

It is an interprime number because it is at equal distance from previous prime (7998637) and next prime (7998643).

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

It is not an unprimeable number, because it can be changed into a prime (7998643) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2806 + ... + 4885.

Almost surely, 2^7998640 is an apocalyptic number.

It is an amenable number.

7998640 is an abundant number, since it is smaller than the sum of its proper divisors (12031328).

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

7998640 is a wasteful number, since it uses less digits than its factorization.

7998640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7717 (or 7711 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 43.

The square root of 7998640 is about 2828.1866982220. The cubic root of 7998640 is about 199.9886660244.

The spelling of 7998640 in words is "seven million, nine hundred ninety-eight thousand, six hundred forty".