391234897 has 2 divisors, whose sum is σ = 391234898. Its totient is φ = 391234896.

The previous prime is 391234843. The next prime is 391234903. The reversal of 391234897 is 798432193.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 332114176 + 59120721 = 18224^2 + 7689^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-391234897 is a prime.

It is not a weakly prime, because it can be changed into another prime (391237897) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 195617448 + 195617449.

It is an arithmetic number, because the mean of its divisors is an integer number (195617449).

Almost surely, 2^391234897 is an apocalyptic number.

It is an amenable number.

391234897 is a deficient number, since it is larger than the sum of its proper divisors (1).

391234897 is an equidigital number, since it uses as much as digits as its factorization.

391234897 is an evil number, because the sum of its binary digits is even.

The product of its digits is 326592, while the sum is 46.

The square root of 391234897 is about 19779.6586674290. The cubic root of 391234897 is about 731.3846846470.

It can be divided in two parts, 3912 and 34897, that added together give a square (38809 = 197²).

The spelling of 391234897 in words is "three hundred ninety-one million, two hundred thirty-four thousand, eight hundred ninety-seven".