42074645581 has 2 divisors, whose sum is σ = 42074645582. Its totient is φ = 42074645580.

The previous prime is 42074645521. The next prime is 42074645593. The reversal of 42074645581 is 18554647024.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 26786559556 + 15288086025 = 163666^2 + 123645^2 .

It is a cyclic number.

It is not a de Polignac number, because 42074645581 - 2¹⁵ = 42074612813 is a prime.

It is a super-2 number, since 2×42074645581² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42074645521) 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, 21037322790 + 21037322791.

It is an arithmetic number, because the mean of its divisors is an integer number (21037322791).

Almost surely, 2^42074645581 is an apocalyptic number.

It is an amenable number.

42074645581 is a deficient number, since it is larger than the sum of its proper divisors (1).

42074645581 is an equidigital number, since it uses as much as digits as its factorization.

42074645581 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1075200, while the sum is 46.

It can be divided in two parts, 420746455 and 81, that added together give a triangular number (420746536 = T₂₉₀₀₈).

The spelling of 42074645581 in words is "forty-two billion, seventy-four million, six hundred forty-five thousand, five hundred eighty-one".