172221993 has 24 divisors (see below), whose sum is σ = 251821440. Its totient is φ = 113414400.

The previous prime is 172221983. The next prime is 172222021. The reversal of 172221993 is 399122271.

It is not a de Polignac number, because 172221993 - 2⁴ = 172221977 is a prime.

It is not an unprimeable number, because it can be changed into a prime (172221983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 479548 + ... + 479906.

It is an arithmetic number, because the mean of its divisors is an integer number (10492560).

Almost surely, 2^172221993 is an apocalyptic number.

It is an amenable number.

172221993 is a deficient number, since it is larger than the sum of its proper divisors (79599447).

172221993 is a wasteful number, since it uses less digits than its factorization.

172221993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 869 (or 866 counting only the distinct ones).

The product of its digits is 13608, while the sum is 36.

The square root of 172221993 is about 13123.3377233080. The cubic root of 172221993 is about 556.3689313848.

The spelling of 172221993 in words is "one hundred seventy-two million, two hundred twenty-one thousand, nine hundred ninety-three".