64646641 has 8 divisors (see below), whose sum is σ = 65948904. Its totient is φ = 63352320.

The previous prime is 64646639. The next prime is 64646651. The reversal of 64646641 is 14664646.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 5041 + 64641600 = 71^2 + 8040^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 64646641 - 2¹ = 64646639 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 64646641.

It is not an unprimeable number, because it can be changed into a prime (64646651) 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 7 ways as a sum of consecutive naturals, for example, 16065 + ... + 19681.

It is an arithmetic number, because the mean of its divisors is an integer number (8243613).

Almost surely, 2^64646641 is an apocalyptic number.

64646641 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

It is an amenable number.

64646641 is a deficient number, since it is larger than the sum of its proper divisors (1302263).

64646641 is a wasteful number, since it uses less digits than its factorization.

64646641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3971.

The product of its digits is 82944, while the sum is 37.

The square root of 64646641 is about 8040.3134889132. The cubic root of 64646641 is about 401.3426568886.

The spelling of 64646641 in words is "sixty-four million, six hundred forty-six thousand, six hundred forty-one".