626081821 has 2 divisors, whose sum is σ = 626081822. Its totient is φ = 626081820.

The previous prime is 626081809. The next prime is 626081839. The reversal of 626081821 is 128180626.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 406627225 + 219454596 = 20165^2 + 14814^2 .

It is a cyclic number.

It is not a de Polignac number, because 626081821 - 2¹³ = 626073629 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (626081891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 313040910 + 313040911.

It is an arithmetic number, because the mean of its divisors is an integer number (313040911).

Almost surely, 2^626081821 is an apocalyptic number.

It is an amenable number.

626081821 is a deficient number, since it is larger than the sum of its proper divisors (1).

626081821 is an equidigital number, since it uses as much as digits as its factorization.

626081821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9216, while the sum is 34.

The square root of 626081821 is about 25021.6270654008. The cubic root of 626081821 is about 855.4809924268.

The spelling of 626081821 in words is "six hundred twenty-six million, eighty-one thousand, eight hundred twenty-one".