42156323521 has 12 divisors (see below), whose sum is σ = 45598970172. Its totient is φ = 38742974784.

The previous prime is 42156323501. The next prime is 42156323527. The reversal of 42156323521 is 12532365124.

It can be written as a sum of positive squares in 6 ways, for example, as 2410319025 + 39746004496 = 49095^2 + 199364^2 .

It is not a de Polignac number, because 42156323521 - 2⁹ = 42156323009 is a prime.

It is a super-2 number, since 2×42156323521² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42156323527) 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 11 ways as a sum of consecutive naturals, for example, 650815 + ... + 712651.

It is an arithmetic number, because the mean of its divisors is an integer number (3799914181).

Almost surely, 2^42156323521 is an apocalyptic number.

It is an amenable number.

42156323521 is a deficient number, since it is larger than the sum of its proper divisors (3442646651).

42156323521 is an equidigital number, since it uses as much as digits as its factorization.

42156323521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62308 (or 62079 counting only the distinct ones).

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

Adding to 42156323521 its reverse (12532365124), we get a palindrome (54688688645).

The spelling of 42156323521 in words is "forty-two billion, one hundred fifty-six million, three hundred twenty-three thousand, five hundred twenty-one".