65639745 has 24 divisors (see below), whose sum is σ = 113968296. Its totient is φ = 34948608.

The previous prime is 65639701. The next prime is 65639767. The reversal of 65639745 is 54793656.

65639745 is a `hidden beast` number, since 6 + 5 + 639 + 7 + 4 + 5 = 666.

65639745 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 33558849 + 32080896 = 5793^2 + 5664^2 .

It is not a de Polignac number, because 65639745 - 2¹⁵ = 65606977 is a prime.

It is a super-2 number, since 2×65639745² = 8617152247330050, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 65639745.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 43219 + ... + 44711.

It is an arithmetic number, because the mean of its divisors is an integer number (4748679).

Almost surely, 2^65639745 is an apocalyptic number.

It is an amenable number.

65639745 is a deficient number, since it is larger than the sum of its proper divisors (48328551).

65639745 is a wasteful number, since it uses less digits than its factorization.

65639745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2481 (or 2478 counting only the distinct ones).

The product of its digits is 680400, while the sum is 45.

The square root of 65639745 is about 8101.8359030531. The cubic root of 65639745 is about 403.3873687745.

It can be divided in two parts, 656 and 39745, that added together give a square (40401 = 201²).

The spelling of 65639745 in words is "sixty-five million, six hundred thirty-nine thousand, seven hundred forty-five".