645431400043 has 2 divisors, whose sum is σ = 645431400044. Its totient is φ = 645431400042.

The previous prime is 645431399989. The next prime is 645431400071. The reversal of 645431400043 is 340004134546.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 645431400043 - 2⁹ = 645431399531 is a prime.

It is a super-2 number, since 2×645431400043² (a number of 24 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 645431399981 and 645431400008.

It is not a weakly prime, because it can be changed into another prime (645431400443) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322715700021 + 322715700022.

It is an arithmetic number, because the mean of its divisors is an integer number (322715700022).

Almost surely, 2^645431400043 is an apocalyptic number.

645431400043 is a deficient number, since it is larger than the sum of its proper divisors (1).

645431400043 is an equidigital number, since it uses as much as digits as its factorization.

645431400043 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 69120, while the sum is 34.

Adding to 645431400043 its reverse (340004134546), we get a palindrome (985435534589).

The spelling of 645431400043 in words is "six hundred forty-five billion, four hundred thirty-one million, four hundred thousand, forty-three".