Search a number
-
+
660661 is a prime number
BaseRepresentation
bin10100001010010110101
31020120020221
42201102311
5132120121
622054341
75421061
oct2412265
91216227
10660661
11411401
1227a3b1
131a1931
14132aa1
15d0b41
hexa14b5

660661 has 2 divisors, whose sum is σ = 660662. Its totient is φ = 660660.

The previous prime is 660659. The next prime is 660683. The reversal of 660661 is 166066.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 649636 + 11025 = 806^2 + 105^2 .

It is a cyclic number.

It is not a de Polignac number, because 660661 - 21 = 660659 is a prime.

It is a super-4 number, since 4×6606614 (a number of 24 digits) contains 4444 as substring.

Together with 660659, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (660601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330330 + 330331.

It is an arithmetic number, because the mean of its divisors is an integer number (330331).

2660661 is an apocalyptic number.

660661 is the 364-th centered decagonal number.

It is an amenable number.

660661 is a deficient number, since it is larger than the sum of its proper divisors (1).

660661 is an equidigital number, since it uses as much as digits as its factorization.

660661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 660661 is about 812.8105560338. The cubic root of 660661 is about 87.0949331454.

The spelling of 660661 in words is "six hundred sixty thousand, six hundred sixty-one".