9665551 has 4 divisors (see below), whose sum is σ = 11046352. Its totient is φ = 8284752.

The previous prime is 9665527. The next prime is 9665567. The reversal of 9665551 is 1555669.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1555669 = 83 ⋅18743.

It is not a de Polignac number, because 9665551 - 2⁵ = 9665519 is a prime.

It is a super-2 number, since 2×9665551² = 186845752267202, which contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 9665551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9665501) 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, 690390 + ... + 690403.

It is an arithmetic number, because the mean of its divisors is an integer number (2761588).

Almost surely, 2^9665551 is an apocalyptic number.

9665551 is a deficient number, since it is larger than the sum of its proper divisors (1380801).

9665551 is a wasteful number, since it uses less digits than its factorization.

9665551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1380800.

The product of its digits is 40500, while the sum is 37.

The square root of 9665551 is about 3108.9469278198. The cubic root of 9665551 is about 213.0143553845.

The spelling of 9665551 in words is "nine million, six hundred sixty-five thousand, five hundred fifty-one".