671991629 has 2 divisors, whose sum is σ = 671991630. Its totient is φ = 671991628.

The previous prime is 671991613. The next prime is 671991643. The reversal of 671991629 is 926199176.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 576480100 + 95511529 = 24010^2 + 9773^2 .

It is a cyclic number.

It is not a de Polignac number, because 671991629 - 2⁴ = 671991613 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (671990629) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 335995814 + 335995815.

It is an arithmetic number, because the mean of its divisors is an integer number (335995815).

Almost surely, 2^671991629 is an apocalyptic number.

It is an amenable number.

671991629 is a deficient number, since it is larger than the sum of its proper divisors (1).

671991629 is an equidigital number, since it uses as much as digits as its factorization.

671991629 is an evil number, because the sum of its binary digits is even.

The product of its digits is 367416, while the sum is 50.

The square root of 671991629 is about 25922.8013339608. The cubic root of 671991629 is about 875.9001909630.

The spelling of 671991629 in words is "six hundred seventy-one million, nine hundred ninety-one thousand, six hundred twenty-nine".