21230177 has 2 divisors, whose sum is σ = 21230178. Its totient is φ = 21230176.

The previous prime is 21230171. The next prime is 21230179. The reversal of 21230177 is 77103212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11015761 + 10214416 = 3319^2 + 3196^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21230177 is a prime.

Together with 21230179, 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 (21230171) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10615088 + 10615089.

It is an arithmetic number, because the mean of its divisors is an integer number (10615089).

Almost surely, 2^21230177 is an apocalyptic number.

It is an amenable number.

21230177 is a deficient number, since it is larger than the sum of its proper divisors (1).

21230177 is an equidigital number, since it uses as much as digits as its factorization.

21230177 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 588, while the sum is 23.

The square root of 21230177 is about 4607.6216207497. The cubic root of 21230177 is about 276.8967584774.

Adding to 21230177 its reverse (77103212), we get a palindrome (98333389).

The spelling of 21230177 in words is "twenty-one million, two hundred thirty thousand, one hundred seventy-seven".