7781648 has 80 divisors (see below), whose sum is σ = 18820224. Its totient is φ = 3041280.

The previous prime is 7781647. The next prime is 7781663. The reversal of 7781648 is 8461877.

It is not an unprimeable number, because it can be changed into a prime (7781647) 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, 116111 + ... + 116177.

Almost surely, 2^7781648 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 7781648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9410112).

7781648 is an abundant number, since it is smaller than the sum of its proper divisors (11038576).

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

7781648 is a wasteful number, since it uses less digits than its factorization.

7781648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160 (or 154 counting only the distinct ones).

The product of its digits is 75264, while the sum is 41.

The square root of 7781648 is about 2789.5605388663. The cubic root of 7781648 is about 198.1635895934.

The spelling of 7781648 in words is "seven million, seven hundred eighty-one thousand, six hundred forty-eight".