1391078285 has 4 divisors (see below), whose sum is σ = 1669293948. Its totient is φ = 1112862624.

The previous prime is 1391078279. The next prime is 1391078303. The reversal of 1391078285 is 5828701931.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5828701931 = 13 ⋅448361687.

It can be written as a sum of positive squares in 2 ways, for example, as 442807849 + 948270436 = 21043^2 + 30794^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1391078285 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 139107824 + ... + 139107833.

It is an arithmetic number, because the mean of its divisors is an integer number (417323487).

Almost surely, 2^1391078285 is an apocalyptic number.

It is an amenable number.

1391078285 is a deficient number, since it is larger than the sum of its proper divisors (278215663).

1391078285 is an equidigital number, since it uses as much as digits as its factorization.

1391078285 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 278215662.

The product of its (nonzero) digits is 120960, while the sum is 44.

The square root of 1391078285 is about 37297.1618893449. The cubic root of 1391078285 is about 1116.3075372447.

The spelling of 1391078285 in words is "one billion, three hundred ninety-one million, seventy-eight thousand, two hundred eighty-five".