8621661 has 4 divisors (see below), whose sum is σ = 11495552. Its totient is φ = 5747772.

The previous prime is 8621653. The next prime is 8621677. The reversal of 8621661 is 1661268.

8621661 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

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 not a de Polignac number, because 8621661 - 2³ = 8621653 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8621681) 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, 1436941 + ... + 1436946.

It is an arithmetic number, because the mean of its divisors is an integer number (2873888).

Almost surely, 2^8621661 is an apocalyptic number.

It is an amenable number.

8621661 is a deficient number, since it is larger than the sum of its proper divisors (2873891).

8621661 is a wasteful number, since it uses less digits than its factorization.

8621661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2873890.

The product of its digits is 3456, while the sum is 30.

The square root of 8621661 is about 2936.2665069779. The cubic root of 8621661 is about 205.0518290527.

The spelling of 8621661 in words is "eight million, six hundred twenty-one thousand, six hundred sixty-one".