427221391 has 2 divisors, whose sum is σ = 427221392. Its totient is φ = 427221390.

The previous prime is 427221371. The next prime is 427221401. The reversal of 427221391 is 193122724.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 427221391 - 2¹⁵ = 427188623 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (427221341) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 213610695 + 213610696.

It is an arithmetic number, because the mean of its divisors is an integer number (213610696).

Almost surely, 2^427221391 is an apocalyptic number.

427221391 is a deficient number, since it is larger than the sum of its proper divisors (1).

427221391 is an equidigital number, since it uses as much as digits as its factorization.

427221391 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6048, while the sum is 31.

The square root of 427221391 is about 20669.3345562938. The cubic root of 427221391 is about 753.1549415528.

The spelling of 427221391 in words is "four hundred twenty-seven million, two hundred twenty-one thousand, three hundred ninety-one".