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670721 = 1733877
BaseRepresentation
bin10100011110000000001
31021002001112
42203300001
5132430341
622213105
75462312
oct2436001
91232045
10670721
11418a17
12284195
131a639c
14136609
15d3aeb
hexa3c01

670721 has 4 divisors (see below), whose sum is σ = 674772. Its totient is φ = 666672.

The previous prime is 670711. The next prime is 670727. The reversal of 670721 is 127076.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 409600 + 261121 = 640^2 + 511^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2k-670721 is a prime.

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

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (670727) 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 in 3 ways as a sum of consecutive naturals, for example, 1766 + ... + 2111.

It is an arithmetic number, because the mean of its divisors is an integer number (168693).

It is a Proth number, since it is equal to 655 ⋅ 210 + 1 and 655 < 210.

2670721 is an apocalyptic number.

It is an amenable number.

670721 is a deficient number, since it is larger than the sum of its proper divisors (4051).

670721 is a wasteful number, since it uses less digits than its factorization.

670721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4050.

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

The square root of 670721 is about 818.9755796115. The cubic root of 670721 is about 87.5347780119.

Adding to 670721 its reverse (127076), we get a palindrome (797797).

The spelling of 670721 in words is "six hundred seventy thousand, seven hundred twenty-one".

Divisors: 1 173 3877 670721