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65421221 is a prime number
BaseRepresentation
bin1111100110001…
…1111110100101
311120002202001012
43321203332211
5113221434341
610254112005
71423033265
oct371437645
9146082035
1065421221
1133a23a28
1219aab605
13107276a8
14898d7a5
155b240eb
hex3e63fa5

65421221 has 2 divisors, whose sum is σ = 65421222. Its totient is φ = 65421220.

The previous prime is 65421211. The next prime is 65421229. The reversal of 65421221 is 12212456.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 65044225 + 376996 = 8065^2 + 614^2 .

It is a cyclic number.

It is not a de Polignac number, because 65421221 - 214 = 65404837 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (65421229) 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, 32710610 + 32710611.

It is an arithmetic number, because the mean of its divisors is an integer number (32710611).

Almost surely, 265421221 is an apocalyptic number.

It is an amenable number.

65421221 is a deficient number, since it is larger than the sum of its proper divisors (1).

65421221 is an equidigital number, since it uses as much as digits as its factorization.

65421221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 960, while the sum is 23.

The square root of 65421221 is about 8088.3385809448. The cubic root of 65421221 is about 402.9392265513.

Adding to 65421221 its reverse (12212456), we get a palindrome (77633677).

The spelling of 65421221 in words is "sixty-five million, four hundred twenty-one thousand, two hundred twenty-one".