9665651 has 4 divisors (see below), whose sum is σ = 9672312. Its totient is φ = 9658992.

The previous prime is 9665641. The next prime is 9665653. The reversal of 9665651 is 1565669.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1565669 = 7 ⋅223667.

It is a cyclic number.

It is not a de Polignac number, because 9665651 - 2⁶ = 9665587 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9665653) 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, 125 + ... + 4398.

It is an arithmetic number, because the mean of its divisors is an integer number (2418078).

Almost surely, 2^9665651 is an apocalyptic number.

9665651 is a deficient number, since it is larger than the sum of its proper divisors (6661).

9665651 is a wasteful number, since it uses less digits than its factorization.

9665651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6660.

The product of its digits is 48600, while the sum is 38.

The square root of 9665651 is about 3108.9630103943. The cubic root of 9665651 is about 213.0150899990.

The spelling of 9665651 in words is "nine million, six hundred sixty-five thousand, six hundred fifty-one".