42915581 has 2 divisors, whose sum is σ = 42915582. Its totient is φ = 42915580.

The previous prime is 42915569. The next prime is 42915611. The reversal of 42915581 is 18551924.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 35402500 + 7513081 = 5950^2 + 2741^2 .

It is a cyclic number.

It is not a de Polignac number, because 42915581 - 2¹⁸ = 42653437 is a prime.

It is a super-2 number, since 2×42915581² = 3683494185135122, 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 (42915541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21457790 + 21457791.

It is an arithmetic number, because the mean of its divisors is an integer number (21457791).

Almost surely, 2^42915581 is an apocalyptic number.

It is an amenable number.

42915581 is a deficient number, since it is larger than the sum of its proper divisors (1).

42915581 is an equidigital number, since it uses as much as digits as its factorization.

42915581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14400, while the sum is 35.

The square root of 42915581 is about 6550.9984735153. The cubic root of 42915581 is about 350.1103896693.

The spelling of 42915581 in words is "forty-two million, nine hundred fifteen thousand, five hundred eighty-one".