223749521 has 2 divisors, whose sum is σ = 223749522. Its totient is φ = 223749520.

The previous prime is 223749509. The next prime is 223749523. The reversal of 223749521 is 125947322.

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., 177848896 + 45900625 = 13336^2 + 6775^2 .

It is a cyclic number.

It is not a de Polignac number, because 223749521 - 2⁶ = 223749457 is a prime.

Together with 223749523, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (223749523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 111874760 + 111874761.

It is an arithmetic number, because the mean of its divisors is an integer number (111874761).

Almost surely, 2^223749521 is an apocalyptic number.

It is an amenable number.

223749521 is a deficient number, since it is larger than the sum of its proper divisors (1).

223749521 is an equidigital number, since it uses as much as digits as its factorization.

223749521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30240, while the sum is 35.

The square root of 223749521 is about 14958.2592904388. The cubic root of 223749521 is about 607.0913403723.

The spelling of 223749521 in words is "two hundred twenty-three million, seven hundred forty-nine thousand, five hundred twenty-one".