42506536021 has 4 divisors (see below), whose sum is σ = 43543280844. Its totient is φ = 41469791200.

The previous prime is 42506535997. The next prime is 42506536057. The reversal of 42506536021 is 12063560524.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14104175121 + 28402360900 = 118761^2 + 168530^2 .

It is a cyclic number.

It is not a de Polignac number, because 42506536021 - 2⁹ = 42506535509 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42506536091) 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 in 3 ways as a sum of consecutive naturals, for example, 518372350 + ... + 518372431.

It is an arithmetic number, because the mean of its divisors is an integer number (10885820211).

Almost surely, 2^42506536021 is an apocalyptic number.

42506536021 is a gapful number since it is divisible by the number (41) formed by its first and last digit.

It is an amenable number.

42506536021 is a deficient number, since it is larger than the sum of its proper divisors (1036744823).

42506536021 is a wasteful number, since it uses less digits than its factorization.

42506536021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1036744822.

The product of its (nonzero) digits is 43200, while the sum is 34.

The spelling of 42506536021 in words is "forty-two billion, five hundred six million, five hundred thirty-six thousand, twenty-one".