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1980005 = 5396001
BaseRepresentation
bin111100011011001100101
310201121001112
413203121211
51001330010
6110234405
722554416
oct7433145
93647045
101980005
111132675
127b5a05
13544301
1439780d
15291a05
hex1e3665

1980005 has 4 divisors (see below), whose sum is σ = 2376012. Its totient is φ = 1584000.

The previous prime is 1979993. The next prime is 1980019. The reversal of 1980005 is 5000891.

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 256036 + 1723969 = 506^2 + 1313^2 .

It is not a de Polignac number, because 1980005 - 26 = 1979941 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 197996 + ... + 198005.

It is an arithmetic number, because the mean of its divisors is an integer number (594003).

21980005 is an apocalyptic number.

It is an amenable number.

1980005 is a deficient number, since it is larger than the sum of its proper divisors (396007).

1980005 is an equidigital number, since it uses as much as digits as its factorization.

1980005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 396006.

The product of its (nonzero) digits is 360, while the sum is 23.

The square root of 1980005 is about 1407.1265046185. The cubic root of 1980005 is about 125.5708292636.

Adding to 1980005 its reverse (5000891), we get a palindrome (6980896).

The spelling of 1980005 in words is "one million, nine hundred eighty thousand, five".

Divisors: 1 5 396001 1980005