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42686821 is a prime number
BaseRepresentation
bin1010001011010…
…1100101100101
32222022201022101
42202311211211
541411434241
64122532101
71025555242
oct242654545
988281271
1042686821
1122106271
1212367031
138ac7798
1459525c9
153b32e31
hex28b5965

42686821 has 2 divisors, whose sum is σ = 42686822. Its totient is φ = 42686820.

The previous prime is 42686801. The next prime is 42686837. The reversal of 42686821 is 12868624.

42686821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 27562500 + 15124321 = 5250^2 + 3889^2 .

It is a cyclic number.

It is not a de Polignac number, because 42686821 - 217 = 42555749 is a prime.

It is a super-3 number, since 3×426868213 (a number of 24 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42686801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21343410 + 21343411.

It is an arithmetic number, because the mean of its divisors is an integer number (21343411).

Almost surely, 242686821 is an apocalyptic number.

It is an amenable number.

42686821 is a deficient number, since it is larger than the sum of its proper divisors (1).

42686821 is an equidigital number, since it uses as much as digits as its factorization.

42686821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36864, while the sum is 37.

The square root of 42686821 is about 6533.5152100535. The cubic root of 42686821 is about 349.4871973332.

The spelling of 42686821 in words is "forty-two million, six hundred eighty-six thousand, eight hundred twenty-one".