221630477 has 2 divisors, whose sum is σ = 221630478. Its totient is φ = 221630476.

The previous prime is 221630447. The next prime is 221630489. The reversal of 221630477 is 774036122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 124233316 + 97397161 = 11146^2 + 9869^2 .

It is a cyclic number.

It is not a de Polignac number, because 221630477 - 2⁶ = 221630413 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221630417) 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, 110815238 + 110815239.

It is an arithmetic number, because the mean of its divisors is an integer number (110815239).

Almost surely, 2^221630477 is an apocalyptic number.

It is an amenable number.

221630477 is a deficient number, since it is larger than the sum of its proper divisors (1).

221630477 is an equidigital number, since it uses as much as digits as its factorization.

221630477 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 14112, while the sum is 32.

The square root of 221630477 is about 14887.2588813388. The cubic root of 221630477 is about 605.1687501402.

Adding to 221630477 its reverse (774036122), we get a palindrome (995666599).

The spelling of 221630477 in words is "two hundred twenty-one million, six hundred thirty thousand, four hundred seventy-seven".