154223221 has 2 divisors, whose sum is σ = 154223222. Its totient is φ = 154223220.

The previous prime is 154223219. The next prime is 154223243. The reversal of 154223221 is 122322451.

It is a happy number.

It is an a-pointer prime, because the next prime (154223243) can be obtained adding 154223221 to its sum of digits (22).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 85100625 + 69122596 = 9225^2 + 8314^2 .

It is a cyclic number.

It is not a de Polignac number, because 154223221 - 2¹ = 154223219 is a prime.

It is a super-2 number, since 2×154223221² = 47569603791229682, which contains 22 as substring.

Together with 154223219, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 154223192 and 154223201.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (154223261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77111610 + 77111611.

It is an arithmetic number, because the mean of its divisors is an integer number (77111611).

Almost surely, 2^154223221 is an apocalyptic number.

It is an amenable number.

154223221 is a deficient number, since it is larger than the sum of its proper divisors (1).

154223221 is an equidigital number, since it uses as much as digits as its factorization.

154223221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 960, while the sum is 22.

The square root of 154223221 is about 12418.6642196333. The cubic root of 154223221 is about 536.2696963187.

Adding to 154223221 its reverse (122322451), we get a palindrome (276545672).

The spelling of 154223221 in words is "one hundred fifty-four million, two hundred twenty-three thousand, two hundred twenty-one".