221020004 has 6 divisors (see below), whose sum is σ = 386785014. Its totient is φ = 110510000.

The previous prime is 221020003. The next prime is 221020039. The reversal of 221020004 is 400020122.

It can be written as a sum of positive squares in only one way, i.e., 196000000 + 25020004 = 14000^2 + 5002^2 .

It is not an unprimeable number, because it can be changed into a prime (221020001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27627497 + ... + 27627504.

It is an arithmetic number, because the mean of its divisors is an integer number (64464169).

Almost surely, 2^221020004 is an apocalyptic number.

It is an amenable number.

221020004 is a deficient number, since it is larger than the sum of its proper divisors (165765010).

221020004 is a wasteful number, since it uses less digits than its factorization.

221020004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55255005 (or 55255003 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 11.

The square root of 221020004 is about 14866.7415394228. The cubic root of 221020004 is about 604.6126008391.

Adding to 221020004 its reverse (400020122), we get a palindrome (621040126).

The spelling of 221020004 in words is "two hundred twenty-one million, twenty thousand, four".