221121004004 has 6 divisors (see below), whose sum is σ = 386961757014. Its totient is φ = 110560502000.

The previous prime is 221121003991. The next prime is 221121004021. The reversal of 221121004004 is 400400121122.

It can be written as a sum of positive squares in only one way, i.e., 124325349604 + 96795654400 = 352598^2 + 311120^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27640125497 + ... + 27640125504.

It is an arithmetic number, because the mean of its divisors is an integer number (64493626169).

Almost surely, 2^221121004004 is an apocalyptic number.

It is an amenable number.

221121004004 is a deficient number, since it is larger than the sum of its proper divisors (165840753010).

221121004004 is a wasteful number, since it uses less digits than its factorization.

221121004004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55280251005 (or 55280251003 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 221121004004 its reverse (400400121122), we get a palindrome (621521125126).

The spelling of 221121004004 in words is "two hundred twenty-one billion, one hundred twenty-one million, four thousand, four".