7643665 has 4 divisors (see below), whose sum is σ = 9172404. Its totient is φ = 6114928.

The previous prime is 7643663. The next prime is 7643677. The reversal of 7643665 is 5663467.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2585664 + 5058001 = 1608^2 + 2249^2 .

It is a cyclic number.

It is not a de Polignac number, because 7643665 - 2¹ = 7643663 is a prime.

It is a super-2 number, since 2×7643665² = 116851229264450, which contains 22 as substring.

It is a d-powerful number, because it can be written as 7⁸ + 6⁴ + 4⁷ + 3¹¹ + 6⁴ + 6⁸ + 5⁵ .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7643663) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 764362 + ... + 764371.

It is an arithmetic number, because the mean of its divisors is an integer number (2293101).

Almost surely, 2^7643665 is an apocalyptic number.

It is an amenable number.

7643665 is a deficient number, since it is larger than the sum of its proper divisors (1528739).

7643665 is a wasteful number, since it uses less digits than its factorization.

7643665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1528738.

The product of its digits is 90720, while the sum is 37.

The square root of 7643665 is about 2764.7178879589. The cubic root of 7643665 is about 196.9853287708.

The spelling of 7643665 in words is "seven million, six hundred forty-three thousand, six hundred sixty-five".