9655664921 has 16 divisors (see below), whose sum is σ = 11504744064. Its totient is φ = 7931274624.

The previous prime is 9655664917. The next prime is 9655664923. The reversal of 9655664921 is 1294665569.

It is not a de Polignac number, because 9655664921 - 2² = 9655664917 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (53).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9655664923) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 286676 + ... + 318581.

It is an arithmetic number, because the mean of its divisors is an integer number (719046504).

Almost surely, 2^9655664921 is an apocalyptic number.

It is an amenable number.

9655664921 is a deficient number, since it is larger than the sum of its proper divisors (1849079143).

9655664921 is a wasteful number, since it uses less digits than its factorization.

9655664921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 605360.

The product of its digits is 3499200, while the sum is 53.

The square root of 9655664921 is about 98263.2429802721. The cubic root of 9655664921 is about 2129.4170578838.

The spelling of 9655664921 in words is "nine billion, six hundred fifty-five million, six hundred sixty-four thousand, nine hundred twenty-one".