64640123 has 2 divisors, whose sum is σ = 64640124. Its totient is φ = 64640122.

The previous prime is 64640119. The next prime is 64640129. The reversal of 64640123 is 32104646.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 64640123 - 2² = 64640119 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 64640092 and 64640101.

It is not a weakly prime, because it can be changed into another prime (64640129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32320061 + 32320062.

It is an arithmetic number, because the mean of its divisors is an integer number (32320062).

Almost surely, 2^64640123 is an apocalyptic number.

64640123 is a deficient number, since it is larger than the sum of its proper divisors (1).

64640123 is an equidigital number, since it uses as much as digits as its factorization.

64640123 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 26.

The square root of 64640123 is about 8039.9081462415. The cubic root of 64640123 is about 401.3291679725.

Adding to 64640123 its reverse (32104646), we get a palindrome (96744769).

The spelling of 64640123 in words is "sixty-four million, six hundred forty thousand, one hundred twenty-three".