221221200042 has 12 divisors (see below), whose sum is σ = 479312600130. Its totient is φ = 73740400008.

The previous prime is 221221200037. The next prime is 221221200089. The reversal of 221221200042 is 240002122122.

It can be written as a sum of positive squares in only one way, i.e., 140775790401 + 80445409641 = 375201^2 + 283629^2 .

It is a Harshad number since it is a multiple of its sum of digits (18), and also a Moran number because the ratio is a prime number: 12290066669 = 221221200042 / (2 + 2 + 1 + 2 + 2 + 1 + 2 + 0 + 0 + 0 + 4 + 2).

It is a junction number, because it is equal to n+sod(n) for n = 221221199988 and 221221200024.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6145033317 + ... + 6145033352.

Almost surely, 2^221221200042 is an apocalyptic number.

221221200042 is an abundant number, since it is smaller than the sum of its proper divisors (258091400088).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221221200042 is a wasteful number, since it uses less digits than its factorization.

221221200042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12290066677 (or 12290066674 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

Adding to 221221200042 its reverse (240002122122), we get a palindrome (461223322164).

The spelling of 221221200042 in words is "two hundred twenty-one billion, two hundred twenty-one million, two hundred thousand, forty-two".