108131721 has 4 divisors (see below), whose sum is σ = 144175632. Its totient is φ = 72087812.

The previous prime is 108131701. The next prime is 108131729. The reversal of 108131721 is 127131801.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 127131801 = 3 ⋅42377267.

It is a cyclic number.

It is not a de Polignac number, because 108131721 - 2⁶ = 108131657 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 108131691 and 108131700.

It is not an unprimeable number, because it can be changed into a prime (108131729) 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, 18021951 + ... + 18021956.

It is an arithmetic number, because the mean of its divisors is an integer number (36043908).

Almost surely, 2^108131721 is an apocalyptic number.

It is an amenable number.

108131721 is a deficient number, since it is larger than the sum of its proper divisors (36043911).

108131721 is an equidigital number, since it uses as much as digits as its factorization.

108131721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36043910.

The product of its (nonzero) digits is 336, while the sum is 24.

The square root of 108131721 is about 10398.6403438142. The cubic root of 108131721 is about 476.4138425396.

The spelling of 108131721 in words is "one hundred eight million, one hundred thirty-one thousand, seven hundred twenty-one".