64643519 has 2 divisors, whose sum is σ = 64643520. Its totient is φ = 64643518.

The previous prime is 64643507. The next prime is 64643531. The reversal of 64643519 is 91534646.

It is a balanced prime because it is at equal distance from previous prime (64643507) and next prime (64643531).

It is a cyclic number.

It is not a de Polignac number, because 64643519 - 2²⁴ = 47866303 is a prime.

It is a super-2 number, since 2×64643519² = 8357569097406722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64643539) 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 as a sum of consecutive naturals, namely, 32321759 + 32321760.

It is an arithmetic number, because the mean of its divisors is an integer number (32321760).

Almost surely, 2^64643519 is an apocalyptic number.

64643519 is a deficient number, since it is larger than the sum of its proper divisors (1).

64643519 is an equidigital number, since it uses as much as digits as its factorization.

64643519 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 77760, while the sum is 38.

The square root of 64643519 is about 8040.1193399103. The cubic root of 64643519 is about 401.3361960634.

The spelling of 64643519 in words is "sixty-four million, six hundred forty-three thousand, five hundred nineteen".