64643633 has 2 divisors, whose sum is σ = 64643634. Its totient is φ = 64643632.

The previous prime is 64643609. The next prime is 64643647. The reversal of 64643633 is 33634646.

It is a happy number.

64643633 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 59413264 + 5230369 = 7708^2 + 2287^2 .

It is a cyclic number.

It is not a de Polignac number, because 64643633 - 2¹⁴ = 64627249 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 64643593 and 64643602.

It is not a weakly prime, because it can be changed into another prime (64643693) by changing a digit.

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 as a sum of consecutive naturals, namely, 32321816 + 32321817.

It is an arithmetic number, because the mean of its divisors is an integer number (32321817).

Almost surely, 2^64643633 is an apocalyptic number.

It is an amenable number.

64643633 is a deficient number, since it is larger than the sum of its proper divisors (1).

64643633 is an equidigital number, since it uses as much as digits as its factorization.

64643633 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 93312, while the sum is 35.

The square root of 64643633 is about 8040.1264293542. The cubic root of 64643633 is about 401.3364319844.

The spelling of 64643633 in words is "sixty-four million, six hundred forty-three thousand, six hundred thirty-three".