646782043 has 2 divisors, whose sum is σ = 646782044. Its totient is φ = 646782042.

The previous prime is 646782029. The next prime is 646782077. The reversal of 646782043 is 340287646.

It is a happy number.

646782043 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-646782043 is a prime.

It is a super-2 number, since 2×646782043² = 836654022294507698, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 646781987 and 646782005.

It is not a weakly prime, because it can be changed into another prime (646782023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323391021 + 323391022.

It is an arithmetic number, because the mean of its divisors is an integer number (323391022).

Almost surely, 2^646782043 is an apocalyptic number.

646782043 is a deficient number, since it is larger than the sum of its proper divisors (1).

646782043 is an equidigital number, since it uses as much as digits as its factorization.

646782043 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 193536, while the sum is 40.

The square root of 646782043 is about 25431.9099361412. The cubic root of 646782043 is about 864.8072422906.

The spelling of 646782043 in words is "six hundred forty-six million, seven hundred eighty-two thousand, forty-three".