212123030309 has 4 divisors (see below), whose sum is σ = 213003209100. Its totient is φ = 211242851520.

The previous prime is 212123030297. The next prime is 212123030311. The reversal of 212123030309 is 903030321212.

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 188288302084 + 23834728225 = 433922^2 + 154385^2 .

It is a cyclic number.

It is not a de Polignac number, because 212123030309 - 2²⁰ = 212121981733 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212123030809) 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, 440089034 + ... + 440089515.

It is an arithmetic number, because the mean of its divisors is an integer number (53250802275).

Almost surely, 2^212123030309 is an apocalyptic number.

It is an amenable number.

212123030309 is a deficient number, since it is larger than the sum of its proper divisors (880178791).

212123030309 is an equidigital number, since it uses as much as digits as its factorization.

212123030309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 880178790.

The product of its (nonzero) digits is 1944, while the sum is 26.

The spelling of 212123030309 in words is "two hundred twelve billion, one hundred twenty-three million, thirty thousand, three hundred nine".