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3999781 is a prime number
BaseRepresentation
bin1111010000100000100101
321112012200001
433100200211
52010443111
6221421301
745666112
oct17204045
97465601
103999781
112292105
12140a831
13aa0746
14761909
155401c1
hex3d0825

3999781 has 2 divisors, whose sum is σ = 3999782. Its totient is φ = 3999780.

The previous prime is 3999773. The next prime is 3999791. The reversal of 3999781 is 1879993.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3207681 + 792100 = 1791^2 + 890^2 .

It is a cyclic number.

It is not a de Polignac number, because 3999781 - 23 = 3999773 is a prime.

It is a super-2 number, since 2×39997812 = 31996496095922, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3999791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1999890 + 1999891.

It is an arithmetic number, because the mean of its divisors is an integer number (1999891).

Almost surely, 23999781 is an apocalyptic number.

It is an amenable number.

3999781 is a deficient number, since it is larger than the sum of its proper divisors (1).

3999781 is an equidigital number, since it uses as much as digits as its factorization.

3999781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 122472, while the sum is 46.

The square root of 3999781 is about 1999.9452492506. The cubic root of 3999781 is about 158.7372081370.

The spelling of 3999781 in words is "three million, nine hundred ninety-nine thousand, seven hundred eighty-one".