66725405 has 4 divisors (see below), whose sum is σ = 80070492. Its totient is φ = 53380320.

The previous prime is 66725389. The next prime is 66725411. The reversal of 66725405 is 50452766.

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 48594841 + 18130564 = 6971^2 + 4258^2 .

It is not a de Polignac number, because 66725405 - 2⁴ = 66725389 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, 6672536 + ... + 6672545.

It is an arithmetic number, because the mean of its divisors is an integer number (20017623).

Almost surely, 2^66725405 is an apocalyptic number.

It is an amenable number.

66725405 is a deficient number, since it is larger than the sum of its proper divisors (13345087).

66725405 is a wasteful number, since it uses less digits than its factorization.

66725405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13345086.

The product of its (nonzero) digits is 50400, while the sum is 35.

The square root of 66725405 is about 8168.5619909504. The cubic root of 66725405 is about 405.5991842168.

The spelling of 66725405 in words is "sixty-six million, seven hundred twenty-five thousand, four hundred five".