397647893 has 2 divisors, whose sum is σ = 397647894. Its totient is φ = 397647892.

The previous prime is 397647869. The next prime is 397647907. The reversal of 397647893 is 398746793.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 245298244 + 152349649 = 15662^2 + 12343^2 .

It is an emirp because it is prime and its reverse (398746793) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 397647893 - 2²⁰ = 396599317 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 (397647853) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 198823946 + 198823947.

It is an arithmetic number, because the mean of its divisors is an integer number (198823947).

Almost surely, 2^397647893 is an apocalyptic number.

It is an amenable number.

397647893 is a deficient number, since it is larger than the sum of its proper divisors (1).

397647893 is an equidigital number, since it uses as much as digits as its factorization.

397647893 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6858432, while the sum is 56.

The square root of 397647893 is about 19941.1106260409. The cubic root of 397647893 is about 735.3592536254.

The spelling of 397647893 in words is "three hundred ninety-seven million, six hundred forty-seven thousand, eight hundred ninety-three".