427221661 has 2 divisors, whose sum is σ = 427221662. Its totient is φ = 427221660.

The previous prime is 427221653. The next prime is 427221673. The reversal of 427221661 is 166122724.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 290191225 + 137030436 = 17035^2 + 11706^2 .

It is a cyclic number.

It is not a de Polignac number, because 427221661 - 2³ = 427221653 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (427221601) 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, 213610830 + 213610831.

It is an arithmetic number, because the mean of its divisors is an integer number (213610831).

Almost surely, 2^427221661 is an apocalyptic number.

It is an amenable number.

427221661 is a deficient number, since it is larger than the sum of its proper divisors (1).

427221661 is an equidigital number, since it uses as much as digits as its factorization.

427221661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8064, while the sum is 31.

The square root of 427221661 is about 20669.3410877077. The cubic root of 427221661 is about 753.1551002151.

The spelling of 427221661 in words is "four hundred twenty-seven million, two hundred twenty-one thousand, six hundred sixty-one".