221864021833 has 2 divisors, whose sum is σ = 221864021834. Its totient is φ = 221864021832.

The previous prime is 221864021831. The next prime is 221864021843. The reversal of 221864021833 is 338120468122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 112029445264 + 109834576569 = 334708^2 + 331413^2 .

It is a cyclic number.

It is not a de Polignac number, because 221864021833 - 2¹ = 221864021831 is a prime.

Together with 221864021831, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (221864021831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110932010916 + 110932010917.

It is an arithmetic number, because the mean of its divisors is an integer number (110932010917).

Almost surely, 2^221864021833 is an apocalyptic number.

It is an amenable number.

221864021833 is a deficient number, since it is larger than the sum of its proper divisors (1).

221864021833 is an equidigital number, since it uses as much as digits as its factorization.

221864021833 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 110592, while the sum is 40.

Adding to 221864021833 its reverse (338120468122), we get a palindrome (559984489955).

The spelling of 221864021833 in words is "two hundred twenty-one billion, eight hundred sixty-four million, twenty-one thousand, eight hundred thirty-three".