397749839 has 2 divisors, whose sum is σ = 397749840. Its totient is φ = 397749838.

The previous prime is 397749823. The next prime is 397749841. The reversal of 397749839 is 938947793.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 397749839 - 2⁴ = 397749823 is a prime.

Together with 397749841, 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 (397709839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 198874919 + 198874920.

It is an arithmetic number, because the mean of its divisors is an integer number (198874920).

Almost surely, 2^397749839 is an apocalyptic number.

397749839 is a deficient number, since it is larger than the sum of its proper divisors (1).

397749839 is an equidigital number, since it uses as much as digits as its factorization.

397749839 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10287648, while the sum is 59.

The square root of 397749839 is about 19943.6666388104. Note that the first 4 decimals coincide. The cubic root of 397749839 is about 735.4220902289.

The spelling of 397749839 in words is "three hundred ninety-seven million, seven hundred forty-nine thousand, eight hundred thirty-nine".