172620191 has 2 divisors, whose sum is σ = 172620192. Its totient is φ = 172620190.

The previous prime is 172620181. The next prime is 172620223. The reversal of 172620191 is 191026271.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 172620191 - 2¹⁴ = 172603807 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (172620101) 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 as a sum of consecutive naturals, namely, 86310095 + 86310096.

It is an arithmetic number, because the mean of its divisors is an integer number (86310096).

Almost surely, 2^172620191 is an apocalyptic number.

172620191 is a deficient number, since it is larger than the sum of its proper divisors (1).

172620191 is an equidigital number, since it uses as much as digits as its factorization.

172620191 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1512, while the sum is 29.

The square root of 172620191 is about 13138.5003329908. The cubic root of 172620191 is about 556.7973986683.

The spelling of 172620191 in words is "one hundred seventy-two million, six hundred twenty thousand, one hundred ninety-one".