221256523 has 2 divisors, whose sum is σ = 221256524. Its totient is φ = 221256522.

The previous prime is 221256521. The next prime is 221256533. The reversal of 221256523 is 325652122.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 221256523 - 2¹ = 221256521 is a prime.

Together with 221256521, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 221256491 and 221256500.

It is not a weakly prime, because it can be changed into another prime (221256521) 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, 110628261 + 110628262.

It is an arithmetic number, because the mean of its divisors is an integer number (110628262).

Almost surely, 2^221256523 is an apocalyptic number.

221256523 is a deficient number, since it is larger than the sum of its proper divisors (1).

221256523 is an equidigital number, since it uses as much as digits as its factorization.

221256523 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7200, while the sum is 28.

The square root of 221256523 is about 14874.6940472737. The cubic root of 221256523 is about 604.8281942776.

The spelling of 221256523 in words is "two hundred twenty-one million, two hundred fifty-six thousand, five hundred twenty-three".