221021221969 has 2 divisors, whose sum is σ = 221021221970. Its totient is φ = 221021221968.

The previous prime is 221021221961. The next prime is 221021222057. The reversal of 221021221969 is 969122120122.

221021221969 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 198503218369 + 22518003600 = 445537^2 + 150060^2 .

It is a cyclic number.

It is not a de Polignac number, because 221021221969 - 2³ = 221021221961 is a prime.

It is a super-2 number, since 2×221021221969² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (221021221961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110510610984 + 110510610985.

It is an arithmetic number, because the mean of its divisors is an integer number (110510610985).

Almost surely, 2^221021221969 is an apocalyptic number.

It is an amenable number.

221021221969 is a deficient number, since it is larger than the sum of its proper divisors (1).

221021221969 is an equidigital number, since it uses as much as digits as its factorization.

221021221969 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15552, while the sum is 37.

The spelling of 221021221969 in words is "two hundred twenty-one billion, twenty-one million, two hundred twenty-one thousand, nine hundred sixty-nine".