42047581 has 2 divisors, whose sum is σ = 42047582. Its totient is φ = 42047580.

The previous prime is 42047573. The next prime is 42047609. The reversal of 42047581 is 18574024.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 36711481 + 5336100 = 6059^2 + 2310^2 .

It is a cyclic number.

It is not a de Polignac number, because 42047581 - 2³ = 42047573 is a prime.

It is a super-2 number, since 2×42047581² = 3535998135903122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42047521) 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, 21023790 + 21023791.

It is an arithmetic number, because the mean of its divisors is an integer number (21023791).

Almost surely, 2^42047581 is an apocalyptic number.

It is an amenable number.

42047581 is a deficient number, since it is larger than the sum of its proper divisors (1).

42047581 is an equidigital number, since it uses as much as digits as its factorization.

42047581 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8960, while the sum is 31.

The square root of 42047581 is about 6484.4106131552. The cubic root of 42047581 is about 347.7338790968.

The spelling of 42047581 in words is "forty-two million, forty-seven thousand, five hundred eighty-one".