9661997 has 4 divisors (see below), whose sum is σ = 9693180. Its totient is φ = 9630816.

The previous prime is 9661991. The next prime is 9662021. The reversal of 9661997 is 7991669.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7991669 = 7 ⋅1141667.

It can be written as a sum of positive squares in 2 ways, for example, as 212521 + 9449476 = 461^2 + 3074^2 .

It is a cyclic number.

It is not a de Polignac number, because 9661997 - 2²⁰ = 8613421 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 (9661991) 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 3 ways as a sum of consecutive naturals, for example, 15122 + ... + 15747.

It is an arithmetic number, because the mean of its divisors is an integer number (2423295).

Almost surely, 2^9661997 is an apocalyptic number.

It is an amenable number.

9661997 is a deficient number, since it is larger than the sum of its proper divisors (31183).

9661997 is a wasteful number, since it uses less digits than its factorization.

9661997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31182.

The product of its digits is 183708, while the sum is 47.

The square root of 9661997 is about 3108.3752990912. The cubic root of 9661997 is about 212.9882438941.

The spelling of 9661997 in words is "nine million, six hundred sixty-one thousand, nine hundred ninety-seven".