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664728481 is a prime number
BaseRepresentation
bin100111100111101…
…111001110100001
31201022210201001101
4213213233032201
52330132302411
6145543234401
722321045624
oct4747571641
91638721041
10664728481
1131124938a
12166748a01
13a793cb81
14643d5dbb
153d5568c1
hex279ef3a1

664728481 has 2 divisors, whose sum is σ = 664728482. Its totient is φ = 664728480.

The previous prime is 664728469. The next prime is 664728499. The reversal of 664728481 is 184827466.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 336539025 + 328189456 = 18345^2 + 18116^2 .

It is a cyclic number.

It is not a de Polignac number, because 664728481 - 219 = 664204193 is a prime.

It is a super-2 number, since 2×6647284812 = 883727906905134722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (664728461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332364240 + 332364241.

It is an arithmetic number, because the mean of its divisors is an integer number (332364241).

Almost surely, 2664728481 is an apocalyptic number.

It is an amenable number.

664728481 is a deficient number, since it is larger than the sum of its proper divisors (1).

664728481 is an equidigital number, since it uses as much as digits as its factorization.

664728481 is an evil number, because the sum of its binary digits is even.

The product of its digits is 516096, while the sum is 46.

The square root of 664728481 is about 25782.3288513664. The cubic root of 664728481 is about 872.7330624258.

The spelling of 664728481 in words is "six hundred sixty-four million, seven hundred twenty-eight thousand, four hundred eighty-one".