42549478561 has 4 divisors (see below), whose sum is σ = 42550244032. Its totient is φ = 42548713092.

The previous prime is 42549478523. The next prime is 42549478583. The reversal of 42549478561 is 16587494524.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 42549478561 - 2²⁹ = 42012607649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42549478501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 292221 + ... + 412906.

It is an arithmetic number, because the mean of its divisors is an integer number (10637561008).

Almost surely, 2^42549478561 is an apocalyptic number.

It is an amenable number.

42549478561 is a deficient number, since it is larger than the sum of its proper divisors (765471).

42549478561 is an equidigital number, since it uses as much as digits as its factorization.

42549478561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 765470.

The product of its digits is 9676800, while the sum is 55.

The spelling of 42549478561 in words is "forty-two billion, five hundred forty-nine million, four hundred seventy-eight thousand, five hundred sixty-one".