9165653621 has 4 divisors (see below), whose sum is σ = 9165845100. Its totient is φ = 9165462144.

The previous prime is 9165653591. The next prime is 9165653659. The reversal of 9165653621 is 1263565619.

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: 1263565619 = 10709 ⋅117991.

It can be written as a sum of positive squares in 2 ways, for example, as 3695424100 + 5470229521 = 60790^2 + 73961^2 .

It is a cyclic number.

It is not a de Polignac number, because 9165653621 - 2⁶ = 9165653557 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 (9165653671) 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, 47045 + ... + 143333.

It is an arithmetic number, because the mean of its divisors is an integer number (2291461275).

Almost surely, 2^9165653621 is an apocalyptic number.

It is an amenable number.

9165653621 is a deficient number, since it is larger than the sum of its proper divisors (191479).

9165653621 is an equidigital number, since it uses as much as digits as its factorization.

9165653621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 191478.

The product of its digits is 291600, while the sum is 44.

The square root of 9165653621 is about 95737.4201710073. The cubic root of 9165653621 is about 2092.7682936103.

The spelling of 9165653621 in words is "nine billion, one hundred sixty-five million, six hundred fifty-three thousand, six hundred twenty-one".