221165020642 has 4 divisors (see below), whose sum is σ = 331747530966. Its totient is φ = 110582510320.

The previous prime is 221165020627. The next prime is 221165020673. The reversal of 221165020642 is 246020561122.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 220957343721 + 207676921 = 470061^2 + 14411^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55291255159 + ... + 55291255162.

Almost surely, 2^221165020642 is an apocalyptic number.

221165020642 is a deficient number, since it is larger than the sum of its proper divisors (110582510324).

221165020642 is a wasteful number, since it uses less digits than its factorization.

221165020642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110582510323.

The product of its (nonzero) digits is 11520, while the sum is 31.

Adding to 221165020642 its reverse (246020561122), we get a palindrome (467185581764).

The spelling of 221165020642 in words is "two hundred twenty-one billion, one hundred sixty-five million, twenty thousand, six hundred forty-two".