221420324 has 6 divisors (see below), whose sum is σ = 387485574. Its totient is φ = 110710160.

The previous prime is 221420323. The next prime is 221420347. The reversal of 221420324 is 423024122.

It can be written as a sum of positive squares in only one way, i.e., 166926400 + 54493924 = 12920^2 + 7382^2 .

It is a junction number, because it is equal to n+sod(n) for n = 221420296 and 221420305.

It is not an unprimeable number, because it can be changed into a prime (221420323) 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 as a sum of consecutive naturals, namely, 27677537 + ... + 27677544.

It is an arithmetic number, because the mean of its divisors is an integer number (64580929).

Almost surely, 2^221420324 is an apocalyptic number.

It is an amenable number.

221420324 is a deficient number, since it is larger than the sum of its proper divisors (166065250).

221420324 is a wasteful number, since it uses less digits than its factorization.

221420324 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55355085 (or 55355083 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 20.

The square root of 221420324 is about 14880.1990578083. The cubic root of 221420324 is about 604.9774132678.

Adding to 221420324 its reverse (423024122), we get a palindrome (644444446).

The spelling of 221420324 in words is "two hundred twenty-one million, four hundred twenty thousand, three hundred twenty-four".