221427971 has 2 divisors, whose sum is σ = 221427972. Its totient is φ = 221427970.

The previous prime is 221427967. The next prime is 221427989. The reversal of 221427971 is 179724122.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 221427971 - 2² = 221427967 is a prime.

It is not a weakly prime, because it can be changed into another prime (221427901) 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, 110713985 + 110713986.

It is an arithmetic number, because the mean of its divisors is an integer number (110713986).

Almost surely, 2^221427971 is an apocalyptic number.

221427971 is a deficient number, since it is larger than the sum of its proper divisors (1).

221427971 is an equidigital number, since it uses as much as digits as its factorization.

221427971 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14112, while the sum is 35.

The square root of 221427971 is about 14880.4560077976. The cubic root of 221427971 is about 604.9843777129.

The spelling of 221427971 in words is "two hundred twenty-one million, four hundred twenty-seven thousand, nine hundred seventy-one".