7643661 has 4 divisors (see below), whose sum is σ = 10191552. Its totient is φ = 5095772.

The previous prime is 7643633. The next prime is 7643663. The reversal of 7643661 is 1663467.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 7643661 - 2⁷ = 7643533 is a prime.

It is a congruent 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, 1273941 + ... + 1273946.

It is an arithmetic number, because the mean of its divisors is an integer number (2547888).

Almost surely, 2^7643661 is an apocalyptic number.

It is an amenable number.

7643661 is a deficient number, since it is larger than the sum of its proper divisors (2547891).

7643661 is a wasteful number, since it uses less digits than its factorization.

7643661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2547890.

The product of its digits is 18144, while the sum is 33.

The square root of 7643661 is about 2764.7171645577. The cubic root of 7643661 is about 196.9852944093.

The spelling of 7643661 in words is "seven million, six hundred forty-three thousand, six hundred sixty-one".