Search a number
-
+
66432221 is a prime number
BaseRepresentation
bin1111110101101…
…0110011011101
311122000002212122
43331122303131
5114001312341
610331512325
71434443642
oct375326335
9148002778
1066432221
1134554569
121a2b86a5
13109bc90b
148b73dc9
155c7394b
hex3f5acdd

66432221 has 2 divisors, whose sum is σ = 66432222. Its totient is φ = 66432220.

The previous prime is 66432217. The next prime is 66432229. The reversal of 66432221 is 12223466.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 46308025 + 20124196 = 6805^2 + 4486^2 .

It is a cyclic number.

It is not a de Polignac number, because 66432221 - 22 = 66432217 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a nialpdrome in base 10.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66432229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33216110 + 33216111.

It is an arithmetic number, because the mean of its divisors is an integer number (33216111).

Almost surely, 266432221 is an apocalyptic number.

It is an amenable number.

66432221 is a deficient number, since it is larger than the sum of its proper divisors (1).

66432221 is an equidigital number, since it uses as much as digits as its factorization.

66432221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3456, while the sum is 26.

The square root of 66432221 is about 8150.5963585495. The cubic root of 66432221 is about 405.0042594685.

Adding to 66432221 its reverse (12223466), we get a palindrome (78655687).

The spelling of 66432221 in words is "sixty-six million, four hundred thirty-two thousand, two hundred twenty-one".