108256721 has 4 divisors (see below), whose sum is σ = 108322212. Its totient is φ = 108191232.

The previous prime is 108256717. The next prime is 108256727. The reversal of 108256721 is 127652801.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 127652801 = 701 ⋅182101.

It can be written as a sum of positive squares in 2 ways, for example, as 105349696 + 2907025 = 10264^2 + 1705^2 .

It is a cyclic number.

It is not a de Polignac number, because 108256721 - 2² = 108256717 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (108256727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30200 + ... + 33593.

It is an arithmetic number, because the mean of its divisors is an integer number (27080553).

Almost surely, 2^108256721 is an apocalyptic number.

It is an amenable number.

108256721 is a deficient number, since it is larger than the sum of its proper divisors (65491).

108256721 is an equidigital number, since it uses as much as digits as its factorization.

108256721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65490.

The product of its (nonzero) digits is 6720, while the sum is 32.

The square root of 108256721 is about 10404.6490089767. The cubic root of 108256721 is about 476.5973495848.

The spelling of 108256721 in words is "one hundred eight million, two hundred fifty-six thousand, seven hundred twenty-one".