65920609 has 4 divisors (see below), whose sum is σ = 66661380. Its totient is φ = 65179840.

The previous prime is 65920597. The next prime is 65920619. The reversal of 65920609 is 90602956.

It is a happy number.

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 20223009 + 45697600 = 4497^2 + 6760^2 .

It is a cyclic number.

It is not a de Polignac number, because 65920609 - 2⁹ = 65920097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (65920619) 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, 370252 + ... + 370429.

It is an arithmetic number, because the mean of its divisors is an integer number (16665345).

Almost surely, 2^65920609 is an apocalyptic number.

It is an amenable number.

65920609 is a deficient number, since it is larger than the sum of its proper divisors (740771).

65920609 is an equidigital number, since it uses as much as digits as its factorization.

65920609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 740770.

The product of its (nonzero) digits is 29160, while the sum is 37.

The square root of 65920609 is about 8119.1507560828. The cubic root of 65920609 is about 403.9618976091.

It can be divided in two parts, 65920 and 609, that multiplied together give a triangular number (40145280 = T₈₉₆₀).

The spelling of 65920609 in words is "sixty-five million, nine hundred twenty thousand, six hundred nine".