42553601665 has 4 divisors (see below), whose sum is σ = 51064322004. Its totient is φ = 34042881328.

The previous prime is 42553601633. The next prime is 42553601677. The reversal of 42553601665 is 56610635524.

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 6705480769 + 35848120896 = 81887^2 + 189336^2 .

It is a cyclic number.

It is not a de Polignac number, because 42553601665 - 2⁵ = 42553601633 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4255360162 + ... + 4255360171.

It is an arithmetic number, because the mean of its divisors is an integer number (12766080501).

Almost surely, 2^42553601665 is an apocalyptic number.

It is an amenable number.

42553601665 is a deficient number, since it is larger than the sum of its proper divisors (8510720339).

42553601665 is an equidigital number, since it uses as much as digits as its factorization.

42553601665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8510720338.

The product of its (nonzero) digits is 648000, while the sum is 43.

The spelling of 42553601665 in words is "forty-two billion, five hundred fifty-three million, six hundred one thousand, six hundred sixty-five".