102172321 has 4 divisors (see below), whose sum is σ = 102194500. Its totient is φ = 102150144.

The previous prime is 102172297. The next prime is 102172327. The reversal of 102172321 is 123271201.

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 12680721 + 89491600 = 3561^2 + 9460^2 .

It is a cyclic number.

It is not a de Polignac number, because 102172321 - 2⁵ = 102172289 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (102172327) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1296 + ... + 14353.

It is an arithmetic number, because the mean of its divisors is an integer number (25548625).

Almost surely, 2^102172321 is an apocalyptic number.

It is an amenable number.

102172321 is a deficient number, since it is larger than the sum of its proper divisors (22179).

102172321 is an equidigital number, since it uses as much as digits as its factorization.

102172321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22178.

The product of its (nonzero) digits is 168, while the sum is 19.

The square root of 102172321 is about 10108.0324989584. The cubic root of 102172321 is about 467.4958425665.

The spelling of 102172321 in words is "one hundred two million, one hundred seventy-two thousand, three hundred twenty-one".