221890305 has 32 divisors (see below), whose sum is σ = 436955904. Its totient is φ = 93632256.

The previous prime is 221890301. The next prime is 221890309. The reversal of 221890305 is 503098122.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (221890301) and next prime (221890309).

It is not a de Polignac number, because 221890305 - 2² = 221890301 is a prime.

It is not an unprimeable number, because it can be changed into a prime (221890301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 79914 + ... + 82643.

It is an arithmetic number, because the mean of its divisors is an integer number (13654872).

Almost surely, 2^221890305 is an apocalyptic number.

It is an amenable number.

221890305 is a deficient number, since it is larger than the sum of its proper divisors (215065599).

221890305 is a wasteful number, since it uses less digits than its factorization.

221890305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 162585.

The product of its (nonzero) digits is 4320, while the sum is 30.

The square root of 221890305 is about 14895.9828477345. The cubic root of 221890305 is about 605.4051472000.

The spelling of 221890305 in words is "two hundred twenty-one million, eight hundred ninety thousand, three hundred five".