64686397 has 8 divisors (see below), whose sum is σ = 68056632. Its totient is φ = 61401600.

The previous prime is 64686389. The next prime is 64686403. The reversal of 64686397 is 79368646.

It can be written as a sum of positive squares in 4 ways, for example, as 10310521 + 54375876 = 3211^2 + 7374^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 64686397 - 2³ = 64686389 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 64686397.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64686197) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19804 + ... + 22837.

It is an arithmetic number, because the mean of its divisors is an integer number (8507079).

Almost surely, 2^64686397 is an apocalyptic number.

It is an amenable number.

64686397 is a deficient number, since it is larger than the sum of its proper divisors (3370235).

64686397 is a wasteful number, since it uses less digits than its factorization.

64686397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42719.

The product of its digits is 1306368, while the sum is 49.

The square root of 64686397 is about 8042.7854005935. The cubic root of 64686397 is about 401.4249117887.

It can be divided in two parts, 6468639 and 7, that added together give a palindrome (6468646).

The spelling of 64686397 in words is "sixty-four million, six hundred eighty-six thousand, three hundred ninety-seven".