221801766842 has 4 divisors (see below), whose sum is σ = 332702650266. Its totient is φ = 110900883420.

The previous prime is 221801766833. The next prime is 221801766847. The reversal of 221801766842 is 248667108122.

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., 197108472961 + 24693293881 = 443969^2 + 157141^2 .

It is not an unprimeable number, because it can be changed into a prime (221801766847) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55450441709 + ... + 55450441712.

Almost surely, 2^221801766842 is an apocalyptic number.

221801766842 is a deficient number, since it is larger than the sum of its proper divisors (110900883424).

221801766842 is a wasteful number, since it uses less digits than its factorization.

221801766842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110900883423.

The product of its (nonzero) digits is 516096, while the sum is 47.

The spelling of 221801766842 in words is "two hundred twenty-one billion, eight hundred one million, seven hundred sixty-six thousand, eight hundred forty-two".