42905565454781 has 2 divisors, whose sum is σ = 42905565454782. Its totient is φ = 42905565454780.

The previous prime is 42905565454751. The next prime is 42905565454783. The reversal of 42905565454781 is 18745456550924.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 42905565454756 + 25 = 6550234^2 + 5^2 .

It is a cyclic number.

It is not a de Polignac number, because 42905565454781 - 2¹⁴ = 42905565438397 is a prime.

It is a super-2 number, since 2×42905565454781² (a number of 28 digits) contains 22 as substring.

Together with 42905565454783, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42905565454783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21452782727390 + 21452782727391.

It is an arithmetic number, because the mean of its divisors is an integer number (21452782727391).

Almost surely, 2^{42905565454781} is an apocalyptic number.

It is an amenable number.

42905565454781 is a deficient number, since it is larger than the sum of its proper divisors (1).

42905565454781 is an equidigital number, since it uses as much as digits as its factorization.

42905565454781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 241920000, while the sum is 65.

The spelling of 42905565454781 in words is "forty-two trillion, nine hundred five billion, five hundred sixty-five million, four hundred fifty-four thousand, seven hundred eighty-one".