221005427 has 2 divisors, whose sum is σ = 221005428. Its totient is φ = 221005426.

The previous prime is 221005391. The next prime is 221005429. The reversal of 221005427 is 724500122.

It is a happy number.

221005427 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 221005427 - 2⁶ = 221005363 is a prime.

Together with 221005429, 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 (221005429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110502713 + 110502714.

It is an arithmetic number, because the mean of its divisors is an integer number (110502714).

Almost surely, 2^221005427 is an apocalyptic number.

221005427 is a deficient number, since it is larger than the sum of its proper divisors (1).

221005427 is an equidigital number, since it uses as much as digits as its factorization.

221005427 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1120, while the sum is 23.

The square root of 221005427 is about 14866.2512759606. The cubic root of 221005427 is about 604.5993084802.

Adding to 221005427 its reverse (724500122), we get a palindrome (945505549).

The spelling of 221005427 in words is "two hundred twenty-one million, five thousand, four hundred twenty-seven".