9115613921 has 4 divisors (see below), whose sum is σ = 9122621844. Its totient is φ = 9108606000.

The previous prime is 9115613917. The next prime is 9115613939. The reversal of 9115613921 is 1293165119.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2820778321 + 6294835600 = 53111^2 + 79340^2 .

It is a cyclic number.

It is not a de Polignac number, because 9115613921 - 2² = 9115613917 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9115613321) 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, 3502010 + ... + 3504611.

It is an arithmetic number, because the mean of its divisors is an integer number (2280655461).

Almost surely, 2^9115613921 is an apocalyptic number.

It is an amenable number.

9115613921 is a deficient number, since it is larger than the sum of its proper divisors (7007923).

9115613921 is a wasteful number, since it uses less digits than its factorization.

9115613921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7007922.

The product of its digits is 14580, while the sum is 38.

The square root of 9115613921 is about 95475.7242496751. The cubic root of 9115613921 is about 2088.9528663998.

The spelling of 9115613921 in words is "nine billion, one hundred fifteen million, six hundred thirteen thousand, nine hundred twenty-one".