646223623 has 2 divisors, whose sum is σ = 646223624. Its totient is φ = 646223622.

The previous prime is 646223621. The next prime is 646223639. The reversal of 646223623 is 326322646.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 646223623 - 2¹ = 646223621 is a prime.

It is a super-2 number, since 2×646223623² = 835209941846492258, which contains 22 as substring.

Together with 646223621, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (646223621) 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, 323111811 + 323111812.

It is an arithmetic number, because the mean of its divisors is an integer number (323111812).

Almost surely, 2^646223623 is an apocalyptic number.

646223623 is a deficient number, since it is larger than the sum of its proper divisors (1).

646223623 is an equidigital number, since it uses as much as digits as its factorization.

646223623 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 62208, while the sum is 34.

The square root of 646223623 is about 25420.9288382624. The cubic root of 646223623 is about 864.5582842810.

The spelling of 646223623 in words is "six hundred forty-six million, two hundred twenty-three thousand, six hundred twenty-three".