626781187649 has 2 divisors, whose sum is σ = 626781187650. Its totient is φ = 626781187648.

The previous prime is 626781187607. The next prime is 626781187651. The reversal of 626781187649 is 946781187626.

626781187649 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 438334036624 + 188447151025 = 662068^2 + 434105^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-626781187649 is a prime.

Together with 626781187651, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (626781183649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 313390593824 + 313390593825.

It is an arithmetic number, because the mean of its divisors is an integer number (313390593825).

Almost surely, 2^626781187649 is an apocalyptic number.

It is an amenable number.

626781187649 is a deficient number, since it is larger than the sum of its proper divisors (1).

626781187649 is an equidigital number, since it uses as much as digits as its factorization.

626781187649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 48771072, while the sum is 65.

The spelling of 626781187649 in words is "six hundred twenty-six billion, seven hundred eighty-one million, one hundred eighty-seven thousand, six hundred forty-nine".