42894947581 has 2 divisors, whose sum is σ = 42894947582. Its totient is φ = 42894947580.

The previous prime is 42894947539. The next prime is 42894947617. The reversal of 42894947581 is 18574949824.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 42876328356 + 18619225 = 207066^2 + 4315^2 .

It is a cyclic number.

It is not a de Polignac number, because 42894947581 - 2⁷ = 42894947453 is a prime.

It is a super-2 number, since 2×42894947581² (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 (42894447581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21447473790 + 21447473791.

It is an arithmetic number, because the mean of its divisors is an integer number (21447473791).

Almost surely, 2^42894947581 is an apocalyptic number.

It is an amenable number.

42894947581 is a deficient number, since it is larger than the sum of its proper divisors (1).

42894947581 is an equidigital number, since it uses as much as digits as its factorization.

42894947581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 23224320, while the sum is 61.

The spelling of 42894947581 in words is "forty-two billion, eight hundred ninety-four million, nine hundred forty-seven thousand, five hundred eighty-one".