394972871 has 2 divisors, whose sum is σ = 394972872. Its totient is φ = 394972870.

The previous prime is 394972867. The next prime is 394972873. The reversal of 394972871 is 178279493.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 394972871 - 2² = 394972867 is a prime.

It is a super-3 number, since 3×394972871³ (a number of 27 digits) contains 333 as substring.

It is a Sophie Germain prime.

Together with 394972873, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (394972873) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 197486435 + 197486436.

It is an arithmetic number, because the mean of its divisors is an integer number (197486436).

Almost surely, 2^394972871 is an apocalyptic number.

394972871 is a deficient number, since it is larger than the sum of its proper divisors (1).

394972871 is an equidigital number, since it uses as much as digits as its factorization.

394972871 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 762048, while the sum is 50.

The square root of 394972871 is about 19873.9243985681. The cubic root of 394972871 is about 733.7065941178.

The spelling of 394972871 in words is "three hundred ninety-four million, nine hundred seventy-two thousand, eight hundred seventy-one".