1328256247 has 4 divisors (see below), whose sum is σ = 1328347360. Its totient is φ = 1328165136.

The previous prime is 1328256239. The next prime is 1328256299. The reversal of 1328256247 is 7426528231.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 7426528231 = 5953 ⋅1247527.

It is a 4-Lehmer number, since φ(1328256247) divides (1328256247-1)⁴.

It is a cyclic number.

It is not a de Polignac number, because 1328256247 - 2³ = 1328256239 is a prime.

It is a deceptive number, since it divides R_1328256246.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1328256547) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18222 + ... + 54667.

It is an arithmetic number, because the mean of its divisors is an integer number (332086840).

It is a Poulet number, since it divides 2^1328256246-1.

Almost surely, 2^1328256247 is an apocalyptic number.

1328256247 is the 18223-rd decagonal number.

1328256247 is a deficient number, since it is larger than the sum of its proper divisors (91113).

1328256247 is an equidigital number, since it uses as much as digits as its factorization.

1328256247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91112.

The product of its digits is 161280, while the sum is 40.

The square root of 1328256247 is about 36445.2499922829. The cubic root of 1328256247 is about 1099.2436252048.

The spelling of 1328256247 in words is "one billion, three hundred twenty-eight million, two hundred fifty-six thousand, two hundred forty-seven".