223209256421 has 2 divisors, whose sum is σ = 223209256422. Its totient is φ = 223209256420.

The previous prime is 223209256393. The next prime is 223209256423. The reversal of 223209256421 is 124652902322.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 218037633025 + 5171623396 = 466945^2 + 71914^2 .

It is a cyclic number.

It is not a de Polignac number, because 223209256421 - 2²² = 223205062117 is a prime.

It is a super-3 number, since 3×223209256421³ (a number of 35 digits) contains 333 as substring.

It is a Sophie Germain prime.

Together with 223209256423, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (223209256423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 111604628210 + 111604628211.

It is an arithmetic number, because the mean of its divisors is an integer number (111604628211).

Almost surely, 2^223209256421 is an apocalyptic number.

It is an amenable number.

223209256421 is a deficient number, since it is larger than the sum of its proper divisors (1).

223209256421 is an equidigital number, since it uses as much as digits as its factorization.

223209256421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 103680, while the sum is 38.

The spelling of 223209256421 in words is "two hundred twenty-three billion, two hundred nine million, two hundred fifty-six thousand, four hundred twenty-one".