108915721 has 8 divisors (see below), whose sum is σ = 111875400. Its totient is φ = 105970560.

The previous prime is 108915701. The next prime is 108915731. The reversal of 108915721 is 127519801.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 5625 + 108910096 = 75^2 + 10436^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 108915721 - 2¹⁵ = 108882953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (108915701) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12535 + ... + 19363.

It is an arithmetic number, because the mean of its divisors is an integer number (13984425).

Almost surely, 2^108915721 is an apocalyptic number.

It is an amenable number.

108915721 is a deficient number, since it is larger than the sum of its proper divisors (2959679).

108915721 is an equidigital number, since it uses as much as digits as its factorization.

108915721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7259.

The product of its (nonzero) digits is 5040, while the sum is 34.

The square root of 108915721 is about 10436.2694963287. The cubic root of 108915721 is about 477.5624705599.

The spelling of 108915721 in words is "one hundred eight million, nine hundred fifteen thousand, seven hundred twenty-one".