7581664 has 36 divisors (see below), whose sum is σ = 15461712. Its totient is φ = 3657920.

The previous prime is 7581659. The next prime is 7581667. The reversal of 7581664 is 4661857.

7581664 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (37) coincides with the sum of the digits of its prime factors.

Its product of digits (40320) is a multiple of the sum of its prime divisors (120).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7581667) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 106749 + ... + 106819.

It is an arithmetic number, because the mean of its divisors is an integer number (429492).

Almost surely, 2^7581664 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 7581664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7730856).

7581664 is an abundant number, since it is smaller than the sum of its proper divisors (7880048).

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

7581664 is an equidigital number, since it uses as much as digits as its factorization.

7581664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199 (or 120 counting only the distinct ones).

The product of its digits is 40320, while the sum is 37.

The square root of 7581664 is about 2753.4821590125. The cubic root of 7581664 is about 196.4512717284.

The spelling of 7581664 in words is "seven million, five hundred eighty-one thousand, six hundred sixty-four".