221320427 has 2 divisors, whose sum is σ = 221320428. Its totient is φ = 221320426.

The previous prime is 221320403. The next prime is 221320447. The reversal of 221320427 is 724023122.

It is a happy number.

221320427 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 221320427 - 2¹⁰ = 221319403 is a prime.

It is equal to p_12191261 and since 221320427 and 12191261 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (221320447) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110660213 + 110660214.

It is an arithmetic number, because the mean of its divisors is an integer number (110660214).

Almost surely, 2^221320427 is an apocalyptic number.

221320427 is a deficient number, since it is larger than the sum of its proper divisors (1).

221320427 is an equidigital number, since it uses as much as digits as its factorization.

221320427 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1344, while the sum is 23.

The square root of 221320427 is about 14876.8419699881. The cubic root of 221320427 is about 604.8864181285.

Adding to 221320427 its reverse (724023122), we get a palindrome (945343549).

The spelling of 221320427 in words is "two hundred twenty-one million, three hundred twenty thousand, four hundred twenty-seven".