221213123 has 2 divisors, whose sum is σ = 221213124. Its totient is φ = 221213122.

The previous prime is 221213099. The next prime is 221213147. The reversal of 221213123 is 321312122.

It is a balanced prime because it is at equal distance from previous prime (221213099) and next prime (221213147).

It is a cyclic number.

It is not a de Polignac number, because 221213123 - 2⁸ = 221212867 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (221213173) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110606561 + 110606562.

It is an arithmetic number, because the mean of its divisors is an integer number (110606562).

Almost surely, 2^221213123 is an apocalyptic number.

221213123 is a deficient number, since it is larger than the sum of its proper divisors (1).

221213123 is an equidigital number, since it uses as much as digits as its factorization.

221213123 is an evil number, because the sum of its binary digits is even.

The product of its digits is 144, while the sum is 17.

The square root of 221213123 is about 14873.2351221918. The cubic root of 221213123 is about 604.7886455225.

Adding to 221213123 its reverse (321312122), we get a palindrome (542525245).

The spelling of 221213123 in words is "two hundred twenty-one million, two hundred thirteen thousand, one hundred twenty-three".