212372172209 has 4 divisors (see below), whose sum is σ = 212745410340. Its totient is φ = 211998934080.

The previous prime is 212372172191. The next prime is 212372172301. The reversal of 212372172209 is 902271273212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 18532738225 + 193839433984 = 136135^2 + 440272^2 .

It is a cyclic number.

It is not a de Polignac number, because 212372172209 - 2⁸ = 212372171953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (212372178209) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 186618212 + ... + 186619349.

It is an arithmetic number, because the mean of its divisors is an integer number (53186352585).

Almost surely, 2^212372172209 is an apocalyptic number.

It is an amenable number.

212372172209 is a deficient number, since it is larger than the sum of its proper divisors (373238131).

212372172209 is an equidigital number, since it uses as much as digits as its factorization.

212372172209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 373238130.

The product of its (nonzero) digits is 42336, while the sum is 38.

The spelling of 212372172209 in words is "two hundred twelve billion, three hundred seventy-two million, one hundred seventy-two thousand, two hundred nine".