9661399 has 4 divisors (see below), whose sum is σ = 10539720. Its totient is φ = 8783080.

The previous prime is 9661397. The next prime is 9661409. The reversal of 9661399 is 9931669.

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

It is a cyclic number.

It is not a de Polignac number, because 9661399 - 2¹ = 9661397 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9661391) 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, 439144 + ... + 439165.

It is an arithmetic number, because the mean of its divisors is an integer number (2634930).

Almost surely, 2^9661399 is an apocalyptic number.

9661399 is a deficient number, since it is larger than the sum of its proper divisors (878321).

9661399 is a wasteful number, since it uses less digits than its factorization.

9661399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 878320.

The product of its digits is 78732, while the sum is 43.

The square root of 9661399 is about 3108.2791058719. The cubic root of 9661399 is about 212.9838497163.

The spelling of 9661399 in words is "nine million, six hundred sixty-one thousand, three hundred ninety-nine".