221405145 has 16 divisors (see below), whose sum is σ = 381498432. Its totient is φ = 108999360.

The previous prime is 221405143. The next prime is 221405147. The reversal of 221405145 is 541504122.

It is an interprime number because it is at equal distance from previous prime (221405143) and next prime (221405147).

It is not a de Polignac number, because 221405145 - 2¹ = 221405143 is a prime.

It is not an unprimeable number, because it can be changed into a prime (221405141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 567511 + ... + 567900.

It is an arithmetic number, because the mean of its divisors is an integer number (23843652).

Almost surely, 2^221405145 is an apocalyptic number.

It is an amenable number.

221405145 is a deficient number, since it is larger than the sum of its proper divisors (160093287).

221405145 is a wasteful number, since it uses less digits than its factorization.

221405145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1135432.

The product of its (nonzero) digits is 1600, while the sum is 24.

The square root of 221405145 is about 14879.6890088469. The cubic root of 221405145 is about 604.9635886381.

Adding to 221405145 its reverse (541504122), we get a palindrome (762909267).

The spelling of 221405145 in words is "two hundred twenty-one million, four hundred five thousand, one hundred forty-five".