391099897 has 2 divisors, whose sum is σ = 391099898. Its totient is φ = 391099896.

The previous prime is 391099867. The next prime is 391099927. The reversal of 391099897 is 798990193.

It is a balanced prime because it is at equal distance from previous prime (391099867) and next prime (391099927).

It can be written as a sum of positive squares in only one way, i.e., 292375801 + 98724096 = 17099^2 + 9936^2 .

It is a cyclic number.

It is not a de Polignac number, because 391099897 - 2¹¹ = 391097849 is a prime.

It is not a weakly prime, because it can be changed into another prime (391099847) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 195549948 + 195549949.

It is an arithmetic number, because the mean of its divisors is an integer number (195549949).

Almost surely, 2^391099897 is an apocalyptic number.

It is an amenable number.

391099897 is a deficient number, since it is larger than the sum of its proper divisors (1).

391099897 is an equidigital number, since it uses as much as digits as its factorization.

391099897 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1102248, while the sum is 55.

The square root of 391099897 is about 19776.2457761831. The cubic root of 391099897 is about 731.3005507996.

The spelling of 391099897 in words is "three hundred ninety-one million, ninety-nine thousand, eight hundred ninety-seven".