42646779521 has 2 divisors, whose sum is σ = 42646779522. Its totient is φ = 42646779520.

The previous prime is 42646779503. The next prime is 42646779533. The reversal of 42646779521 is 12597764624.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 41902090000 + 744689521 = 204700^2 + 27289^2 .

It is a cyclic number.

It is not a de Polignac number, because 42646779521 - 2³⁰ = 41573037697 is a prime.

It is not a weakly prime, because it can be changed into another prime (42646772521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21323389760 + 21323389761.

It is an arithmetic number, because the mean of its divisors is an integer number (21323389761).

Almost surely, 2^42646779521 is an apocalyptic number.

It is an amenable number.

42646779521 is a deficient number, since it is larger than the sum of its proper divisors (1).

42646779521 is an equidigital number, since it uses as much as digits as its factorization.

42646779521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5080320, while the sum is 53.

The spelling of 42646779521 in words is "forty-two billion, six hundred forty-six million, seven hundred seventy-nine thousand, five hundred twenty-one".