7640561 has 6 divisors (see below), whose sum is σ = 7752870. Its totient is φ = 7528928.

The previous prime is 7640519. The next prime is 7640579. The reversal of 7640561 is 1650467.

It can be written as a sum of positive squares in 3 ways, for example, as 3763600 + 3876961 = 1940^2 + 1969^2 .

It is a de Polignac number, because none of the positive numbers 2^k-7640561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7640161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 25931 + ... + 26223.

It is an arithmetic number, because the mean of its divisors is an integer number (1292145).

Almost surely, 2^7640561 is an apocalyptic number.

It is an amenable number.

7640561 is a deficient number, since it is larger than the sum of its proper divisors (112309).

7640561 is an frugal number, since it uses more digits than its factorization.

7640561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 675 (or 382 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 29.

The square root of 7640561 is about 2764.1564716926. The cubic root of 7640561 is about 196.9586607066.

The spelling of 7640561 in words is "seven million, six hundred forty thousand, five hundred sixty-one".