7641640 has 32 divisors (see below), whose sum is σ = 17435880. Its totient is φ = 3013632.

The previous prime is 7641637. The next prime is 7641649. The reversal of 7641640 is 461467.

It can be written as a sum of positive squares in 4 ways, for example, as 7540516 + 101124 = 2746^2 + 318^2 .

It is a junction number, because it is equal to n+sod(n) for n = 7641599 and 7641608.

It is not an unprimeable number, because it can be changed into a prime (7641649) 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, 1612 + ... + 4228.

Almost surely, 2^7641640 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 7641640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8717940).

7641640 is an abundant number, since it is smaller than the sum of its proper divisors (9794240).

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

7641640 is a wasteful number, since it uses less digits than its factorization.

7641640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2701 (or 2697 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 28.

The square root of 7641640 is about 2764.3516418864. The cubic root of 7641640 is about 196.9679317707.

It can be divided in two parts, 7641 and 640, that added together give a square (8281 = 91²).

The spelling of 7641640 in words is "seven million, six hundred forty-one thousand, six hundred forty".