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1630721 is a prime number
BaseRepresentation
bin110001110001000000001
310001211221002
412032020001
5404140341
654541345
716601201
oct6161001
93054832
101630721
11a14204
12667855
13451331
14306401
1522329b
hex18e201

1630721 has 2 divisors, whose sum is σ = 1630722. Its totient is φ = 1630720.

The previous prime is 1630669. The next prime is 1630763. The reversal of 1630721 is 1270361.

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., 1575025 + 55696 = 1255^2 + 236^2 .

It is an emirp because it is prime and its reverse (1270361) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2k-1630721 is a prime.

It is a Chen prime.

It is an alternating number because its digits alternate between odd and even.

It is a junction number, because it is equal to n+sod(n) for n = 1630693 and 1630702.

It is not a weakly prime, because it can be changed into another prime (1630771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 815360 + 815361.

It is an arithmetic number, because the mean of its divisors is an integer number (815361).

21630721 is an apocalyptic number.

It is an amenable number.

1630721 is a deficient number, since it is larger than the sum of its proper divisors (1).

1630721 is an equidigital number, since it uses as much as digits as its factorization.

1630721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 252, while the sum is 20.

The square root of 1630721 is about 1276.9968676547. The cubic root of 1630721 is about 117.7045418746.

It can be divided in two parts, 16 and 30721, that multiplied together give a triangular number (491536 = T991).

The spelling of 1630721 in words is "one million, six hundred thirty thousand, seven hundred twenty-one".