172221473 has 2 divisors, whose sum is σ = 172221474. Its totient is φ = 172221472.

The previous prime is 172221457. The next prime is 172221487. The reversal of 172221473 is 374122271.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 167521249 + 4700224 = 12943^2 + 2168^2 .

It is an emirp because it is prime and its reverse (374122271) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 172221473 - 2⁴ = 172221457 is a prime.

It is not a weakly prime, because it can be changed into another prime (172221773) 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 as a sum of consecutive naturals, namely, 86110736 + 86110737.

It is an arithmetic number, because the mean of its divisors is an integer number (86110737).

Almost surely, 2^172221473 is an apocalyptic number.

It is an amenable number.

172221473 is a deficient number, since it is larger than the sum of its proper divisors (1).

172221473 is an equidigital number, since it uses as much as digits as its factorization.

172221473 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4704, while the sum is 29.

The square root of 172221473 is about 13123.3179112601. The cubic root of 172221473 is about 556.3683714251.

It can be divided in two parts, 172 and 221473, that multiplied together give a triangular number (38093356 = T₈₇₂₈).

The spelling of 172221473 in words is "one hundred seventy-two million, two hundred twenty-one thousand, four hundred seventy-three".