391381596409 has 2 divisors, whose sum is σ = 391381596410. Its totient is φ = 391381596408.

The previous prime is 391381596407. The next prime is 391381596439. The reversal of 391381596409 is 904695183193.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 249403356409 + 141978240000 = 499403^2 + 376800^2 .

It is a cyclic number.

It is not a de Polignac number, because 391381596409 - 2¹ = 391381596407 is a prime.

Together with 391381596407, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (391381596401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 195690798204 + 195690798205.

It is an arithmetic number, because the mean of its divisors is an integer number (195690798205).

Almost surely, 2^391381596409 is an apocalyptic number.

It is an amenable number.

391381596409 is a deficient number, since it is larger than the sum of its proper divisors (1).

391381596409 is an equidigital number, since it uses as much as digits as its factorization.

391381596409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6298560, while the sum is 58.

The spelling of 391381596409 in words is "three hundred ninety-one billion, three hundred eighty-one million, five hundred ninety-six thousand, four hundred nine".