209172793 has 2 divisors, whose sum is σ = 209172794. Its totient is φ = 209172792.

The previous prime is 209172773. The next prime is 209172797. The reversal of 209172793 is 397271902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 178569769 + 30603024 = 13363^2 + 5532^2 .

It is a cyclic number.

It is not a de Polignac number, because 209172793 - 2¹³ = 209164601 is a prime.

It is not a weakly prime, because it can be changed into another prime (209172797) 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, 104586396 + 104586397.

It is an arithmetic number, because the mean of its divisors is an integer number (104586397).

Almost surely, 2^209172793 is an apocalyptic number.

It is an amenable number.

209172793 is a deficient number, since it is larger than the sum of its proper divisors (1).

209172793 is an equidigital number, since it uses as much as digits as its factorization.

209172793 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 47628, while the sum is 40.

The square root of 209172793 is about 14462.8072309632. The cubic root of 209172793 is about 593.6107152805.

The spelling of 209172793 in words is "two hundred nine million, one hundred seventy-two thousand, seven hundred ninety-three".