42564021641 has 4 divisors (see below), whose sum is σ = 42584756292. Its totient is φ = 42543286992.

The previous prime is 42564021623. The next prime is 42564021649. The reversal of 42564021641 is 14612046524.

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 16898700025 + 25665321616 = 129995^2 + 160204^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42564021641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42564021649) 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, 10364246 + ... + 10368351.

It is an arithmetic number, because the mean of its divisors is an integer number (10646189073).

Almost surely, 2^42564021641 is an apocalyptic number.

It is an amenable number.

42564021641 is a deficient number, since it is larger than the sum of its proper divisors (20734651).

42564021641 is a wasteful number, since it uses less digits than its factorization.

42564021641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20734650.

The product of its (nonzero) digits is 46080, while the sum is 35.

The spelling of 42564021641 in words is "forty-two billion, five hundred sixty-four million, twenty-one thousand, six hundred forty-one".