221221661002 has 16 divisors (see below), whose sum is σ = 349093216800. Its totient is φ = 104986549360.

The previous prime is 221221660993. The next prime is 221221661009. The reversal of 221221661002 is 200166122122.

It is not an unprimeable number, because it can be changed into a prime (221221661009) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32320024 + ... + 32326867.

It is an arithmetic number, because the mean of its divisors is an integer number (21818326050).

Almost surely, 2^221221661002 is an apocalyptic number.

221221661002 is a deficient number, since it is larger than the sum of its proper divisors (127871555798).

221221661002 is a wasteful number, since it uses less digits than its factorization.

221221661002 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64646981.

The product of its (nonzero) digits is 1152, while the sum is 25.

Adding to 221221661002 its reverse (200166122122), we get a palindrome (421387783124).

The spelling of 221221661002 in words is "two hundred twenty-one billion, two hundred twenty-one million, six hundred sixty-one thousand, two".