6400064641 has 2 divisors, whose sum is σ = 6400064642. Its totient is φ = 6400064640.

The previous prime is 6400064639. The next prime is 6400064653. The reversal of 6400064641 is 1464600046.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4126777600 + 2273287041 = 64240^2 + 47679^2 .

It is a cyclic number.

It is not a de Polignac number, because 6400064641 - 2¹ = 6400064639 is a prime.

Together with 6400064639, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (6400064611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3200032320 + 3200032321.

It is an arithmetic number, because the mean of its divisors is an integer number (3200032321).

Almost surely, 2^6400064641 is an apocalyptic number.

It is an amenable number.

6400064641 is a deficient number, since it is larger than the sum of its proper divisors (1).

6400064641 is an equidigital number, since it uses as much as digits as its factorization.

6400064641 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13824, while the sum is 31.

The square root of 6400064641 is about 80000.4040052299. The cubic root of 6400064641 is about 1856.6417841937.

Adding to 6400064641 its reverse (1464600046), we get a palindrome (7864664687).

The spelling of 6400064641 in words is "six billion, four hundred million, sixty-four thousand, six hundred forty-one".