212109823 has 2 divisors, whose sum is σ = 212109824. Its totient is φ = 212109822.

The previous prime is 212109817. The next prime is 212109827. The reversal of 212109823 is 328901212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 212109823 - 2⁵ = 212109791 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 212109791 and 212109800.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212109827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106054911 + 106054912.

It is an arithmetic number, because the mean of its divisors is an integer number (106054912).

Almost surely, 2^212109823 is an apocalyptic number.

212109823 is a deficient number, since it is larger than the sum of its proper divisors (1).

212109823 is an equidigital number, since it uses as much as digits as its factorization.

212109823 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 212109823 is about 14563.9906275718. The cubic root of 212109823 is about 596.3761410680.

The spelling of 212109823 in words is "two hundred twelve million, one hundred nine thousand, eight hundred twenty-three".