65642405 has 16 divisors (see below), whose sum is σ = 80415984. Its totient is φ = 51425280.

The previous prime is 65642377. The next prime is 65642413. The reversal of 65642405 is 50424656.

It is a Cunningham number, because it is equal to 8102²+1.

It can be written as a sum of positive squares in 8 ways, for example, as 1 + 65642404 = 1^2 + 8102^2 .

It is not a de Polignac number, because 65642405 - 2⁸ = 65642149 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 113477 + ... + 114053.

It is an arithmetic number, because the mean of its divisors is an integer number (5025999).

Almost surely, 2^65642405 is an apocalyptic number.

It is an amenable number.

65642405 is a deficient number, since it is larger than the sum of its proper divisors (14773579).

65642405 is a wasteful number, since it uses less digits than its factorization.

65642405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1016.

The product of its (nonzero) digits is 28800, while the sum is 32.

The square root of 65642405 is about 8102.0000617132. Note that the first 4 decimals coincide. The cubic root of 65642405 is about 403.3928176882.

The spelling of 65642405 in words is "sixty-five million, six hundred forty-two thousand, four hundred five".