391311293 has 2 divisors, whose sum is σ = 391311294. Its totient is φ = 391311292.

The previous prime is 391311281. The next prime is 391311311. The reversal of 391311293 is 392113193.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 379353529 + 11957764 = 19477^2 + 3458^2 .

It is a cyclic number.

It is not a de Polignac number, because 391311293 - 2¹⁸ = 391049149 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (391311493) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 195655646 + 195655647.

It is an arithmetic number, because the mean of its divisors is an integer number (195655647).

Almost surely, 2^391311293 is an apocalyptic number.

It is an amenable number.

391311293 is a deficient number, since it is larger than the sum of its proper divisors (1).

391311293 is an equidigital number, since it uses as much as digits as its factorization.

391311293 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4374, while the sum is 32.

The square root of 391311293 is about 19781.5897490571. The cubic root of 391311293 is about 731.4322871047.

The spelling of 391311293 in words is "three hundred ninety-one million, three hundred eleven thousand, two hundred ninety-three".