154644166223221 has 2 divisors, whose sum is σ = 154644166223222. Its totient is φ = 154644166223220.

The previous prime is 154644166223191. The next prime is 154644166223231. The reversal of 154644166223221 is 122322661446451.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 100716278062500 + 53927888160721 = 10035750^2 + 7343561^2 .

It is a cyclic number.

It is not a de Polignac number, because 154644166223221 - 2¹⁷ = 154644166092149 is a prime.

It is a super-2 number, since 2×154644166223221² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (154644166223231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77322083111610 + 77322083111611.

It is an arithmetic number, because the mean of its divisors is an integer number (77322083111611).

Almost surely, 2^{154644166223221} is an apocalyptic number.

It is an amenable number.

154644166223221 is a deficient number, since it is larger than the sum of its proper divisors (1).

154644166223221 is an equidigital number, since it uses as much as digits as its factorization.

154644166223221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3317760, while the sum is 49.

The spelling of 154644166223221 in words is "one hundred fifty-four trillion, six hundred forty-four billion, one hundred sixty-six million, two hundred twenty-three thousand, two hundred twenty-one".