221009123 has 2 divisors, whose sum is σ = 221009124. Its totient is φ = 221009122.

The previous prime is 221009101. The next prime is 221009143. The reversal of 221009123 is 321900122.

221009123 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an a-pointer prime, because the next prime (221009143) can be obtained adding 221009123 to its sum of digits (20).

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 221009123 - 2⁶ = 221009059 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221009095 and 221009104.

It is not a weakly prime, because it can be changed into another prime (221009143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110504561 + 110504562.

It is an arithmetic number, because the mean of its divisors is an integer number (110504562).

Almost surely, 2^221009123 is an apocalyptic number.

221009123 is a deficient number, since it is larger than the sum of its proper divisors (1).

221009123 is an equidigital number, since it uses as much as digits as its factorization.

221009123 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 221009123 is about 14866.3755838469. The cubic root of 221009123 is about 604.6026788146.

Adding to 221009123 its reverse (321900122), we get a palindrome (542909245).

The spelling of 221009123 in words is "two hundred twenty-one million, nine thousand, one hundred twenty-three".