42387217 has 2 divisors, whose sum is σ = 42387218. Its totient is φ = 42387216.

The previous prime is 42387211. The next prime is 42387287. The reversal of 42387217 is 71278324.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 41679936 + 707281 = 6456^2 + 841^2 .

It is a cyclic number.

It is not a de Polignac number, because 42387217 - 2¹¹ = 42385169 is a prime.

It is not a weakly prime, because it can be changed into another prime (42387211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21193608 + 21193609.

It is an arithmetic number, because the mean of its divisors is an integer number (21193609).

Almost surely, 2^42387217 is an apocalyptic number.

It is an amenable number.

42387217 is a deficient number, since it is larger than the sum of its proper divisors (1).

42387217 is an equidigital number, since it uses as much as digits as its factorization.

42387217 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18816, while the sum is 34.

The square root of 42387217 is about 6510.5465976368. The cubic root of 42387217 is about 348.6676337562.

The spelling of 42387217 in words is "forty-two million, three hundred eighty-seven thousand, two hundred seventeen".