42782581 has 2 divisors, whose sum is σ = 42782582. Its totient is φ = 42782580.

The previous prime is 42782563. The next prime is 42782603. The reversal of 42782581 is 18528724.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 34751025 + 8031556 = 5895^2 + 2834^2 .

It is a cyclic number.

It is not a de Polignac number, because 42782581 - 2¹⁵ = 42749813 is a prime.

It is a super-2 number, since 2×42782581² = 3660698474043122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 42782581.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42782521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21391290 + 21391291.

It is an arithmetic number, because the mean of its divisors is an integer number (21391291).

Almost surely, 2^42782581 is an apocalyptic number.

It is an amenable number.

42782581 is a deficient number, since it is larger than the sum of its proper divisors (1).

42782581 is an equidigital number, since it uses as much as digits as its factorization.

42782581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 35840, while the sum is 37.

The square root of 42782581 is about 6540.8394721167. The cubic root of 42782581 is about 349.7483388188.

It can be divided in two parts, 4278 and 2581, that added together give a cube (6859 = 19³).

The spelling of 42782581 in words is "forty-two million, seven hundred eighty-two thousand, five hundred eighty-one".