671342866021 has 2 divisors, whose sum is σ = 671342866022. Its totient is φ = 671342866020.

The previous prime is 671342865997. The next prime is 671342866027. The reversal of 671342866021 is 120668243176.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 422253036100 + 249089829921 = 649810^2 + 499089^2 .

It is a cyclic number.

It is not a de Polignac number, because 671342866021 - 2⁵ = 671342865989 is a prime.

It is a super-4 number, since 4×671342866021⁴ (a number of 48 digits) contains 4444 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (671342866027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 335671433010 + 335671433011.

It is an arithmetic number, because the mean of its divisors is an integer number (335671433011).

Almost surely, 2^671342866021 is an apocalyptic number.

It is an amenable number.

671342866021 is a deficient number, since it is larger than the sum of its proper divisors (1).

671342866021 is an equidigital number, since it uses as much as digits as its factorization.

671342866021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 580608, while the sum is 46.

The spelling of 671342866021 in words is "six hundred seventy-one billion, three hundred forty-two million, eight hundred sixty-six thousand, twenty-one".