671647901 has 2 divisors, whose sum is σ = 671647902. Its totient is φ = 671647900.

The previous prime is 671647877. The next prime is 671647903. The reversal of 671647901 is 109746176.

671647901 = 18325² + 18326².

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 335842276 + 335805625 = 18326^2 + 18325^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-671647901 is a prime.

It is a super-2 number, since 2×671647901² = 902221805835411602, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 671647903, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (671647903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 335823950 + 335823951.

It is an arithmetic number, because the mean of its divisors is an integer number (335823951).

Almost surely, 2^671647901 is an apocalyptic number.

671647901 is the 18326-th centered square number.

It is an amenable number.

671647901 is a deficient number, since it is larger than the sum of its proper divisors (1).

671647901 is an equidigital number, since it uses as much as digits as its factorization.

671647901 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 63504, while the sum is 41.

The square root of 671647901 is about 25916.1706469146. The cubic root of 671647901 is about 875.7508226496.

The spelling of 671647901 in words is "six hundred seventy-one million, six hundred forty-seven thousand, nine hundred one".