16425640565 has 4 divisors (see below), whose sum is σ = 19710768684. Its totient is φ = 13140512448.

The previous prime is 16425640531. The next prime is 16425640577. The reversal of 16425640565 is 56504652461.

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 3936684049 + 12488956516 = 62743^2 + 111754^2 .

It is a cyclic number.

It is not a de Polignac number, because 16425640565 - 2¹⁴ = 16425624181 is a prime.

It is a Duffinian number.

It is a congruent 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, 1642564052 + ... + 1642564061.

It is an arithmetic number, because the mean of its divisors is an integer number (4927692171).

Almost surely, 2^16425640565 is an apocalyptic number.

It is an amenable number.

16425640565 is a deficient number, since it is larger than the sum of its proper divisors (3285128119).

16425640565 is an equidigital number, since it uses as much as digits as its factorization.

16425640565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3285128118.

The product of its (nonzero) digits is 864000, while the sum is 44.

The spelling of 16425640565 in words is "sixteen billion, four hundred twenty-five million, six hundred forty thousand, five hundred sixty-five".