172273921 has 2 divisors, whose sum is σ = 172273922. Its totient is φ = 172273920.

The previous prime is 172273897. The next prime is 172273963. The reversal of 172273921 is 129372271.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 126900225 + 45373696 = 11265^2 + 6736^2 .

It is a cyclic number.

It is not a de Polignac number, because 172273921 - 2¹⁷ = 172142849 is a prime.

It is not a weakly prime, because it can be changed into another prime (172273991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86136960 + 86136961.

It is an arithmetic number, because the mean of its divisors is an integer number (86136961).

Almost surely, 2^172273921 is an apocalyptic number.

It is an amenable number.

172273921 is a deficient number, since it is larger than the sum of its proper divisors (1).

172273921 is an equidigital number, since it uses as much as digits as its factorization.

172273921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10584, while the sum is 34.

The square root of 172273921 is about 13125.3160342904. The cubic root of 172273921 is about 556.4248441481.

The spelling of 172273921 in words is "one hundred seventy-two million, two hundred seventy-three thousand, nine hundred twenty-one".