212223621 has 4 divisors (see below), whose sum is σ = 282964832. Its totient is φ = 141482412.

The previous prime is 212223611. The next prime is 212223643. The reversal of 212223621 is 126322212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 212223621 - 2⁷ = 212223493 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212223611) 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, 35370601 + ... + 35370606.

It is an arithmetic number, because the mean of its divisors is an integer number (70741208).

Almost surely, 2^212223621 is an apocalyptic number.

It is an amenable number.

212223621 is a deficient number, since it is larger than the sum of its proper divisors (70741211).

212223621 is an equidigital number, since it uses as much as digits as its factorization.

212223621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70741210.

The product of its digits is 576, while the sum is 21.

The square root of 212223621 is about 14567.8969312664. The cubic root of 212223621 is about 596.4827749457.

Adding to 212223621 its reverse (126322212), we get a palindrome (338545833).

The spelling of 212223621 in words is "two hundred twelve million, two hundred twenty-three thousand, six hundred twenty-one".