671639651989 has 2 divisors, whose sum is σ = 671639651990. Its totient is φ = 671639651988.

The previous prime is 671639651983. The next prime is 671639652001. The reversal of 671639651989 is 989156936176.

671639651989 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 can be written as a sum of positive squares in only one way, i.e., 540202950225 + 131436701764 = 734985^2 + 362542^2 .

It is a cyclic number.

It is not a de Polignac number, because 671639651989 - 2³ = 671639651981 is a prime.

It is a super-2 number, since 2×671639651989² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (671639651981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 335819825994 + 335819825995.

It is an arithmetic number, because the mean of its divisors is an integer number (335819825995).

Almost surely, 2^671639651989 is an apocalyptic number.

It is an amenable number.

671639651989 is a deficient number, since it is larger than the sum of its proper divisors (1).

671639651989 is an equidigital number, since it uses as much as digits as its factorization.

671639651989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 132269760, while the sum is 70.

The spelling of 671639651989 in words is "six hundred seventy-one billion, six hundred thirty-nine million, six hundred fifty-one thousand, nine hundred eighty-nine".