223870021 has 2 divisors, whose sum is σ = 223870022.
Its totient is φ = 223870020.
The previous prime is 223869979. The next prime is 223870037. The reversal of 223870021 is 120078322.
It is a strong prime.
It can be written as a sum of positive squares in only one way, i.e., 204633025 + 19236996 = 14305^2 + 4386^2
It is a cyclic number.
It is not a de Polignac number, because 223870021 - 225 = 190315589 is a prime.
It is equal to p12324076 and since 223870021 and 12324076 have the same sum of digits, it is a Honaker prime.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (223870081) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (17) of ones.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 111935010 + 111935011.
It is an arithmetic number, because the mean of its divisors is an integer number (111935011).
Almost surely, 2223870021 is an apocalyptic number.
It is an amenable number.
223870021 is a deficient number, since it is larger than the sum of its proper divisors (1).
223870021 is an equidigital number, since it uses as much as digits as its factorization.
223870021 is an odious number, because the sum of its binary digits is odd.
The product of its (nonzero) digits is 1344, while the sum is 25.
The square root of 223870021 is about 14962.2866233741.
The cubic root of 223870021 is about 607.2003035524.
The spelling of 223870021 in words is "two hundred twenty-three million, eight hundred seventy thousand, twenty-one".