212121423 has 20 divisors (see below), whose sum is σ = 322858008. Its totient is φ = 138743280.

The previous prime is 212121421. The next prime is 212121439. The reversal of 212121423 is 324121212.

It is a happy number.

It is not a de Polignac number, because 212121423 - 2¹ = 212121421 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 212121396 and 212121405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212121421) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 20413 + ... + 28998.

Almost surely, 2^212121423 is an apocalyptic number.

212121423 is a deficient number, since it is larger than the sum of its proper divisors (110736585).

212121423 is an equidigital number, since it uses as much as digits as its factorization.

212121423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49476 (or 49467 counting only the distinct ones).

The product of its digits is 192, while the sum is 18.

The square root of 212121423 is about 14564.3888646246. The cubic root of 212121423 is about 596.3870125386.

Adding to 212121423 its reverse (324121212), we get a palindrome (536242635).

The spelling of 212121423 in words is "two hundred twelve million, one hundred twenty-one thousand, four hundred twenty-three".