6856815025447 has 2 divisors, whose sum is σ = 6856815025448. Its totient is φ = 6856815025446.

The previous prime is 6856815025397. The next prime is 6856815025469. The reversal of 6856815025447 is 7445205186586.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 6856815025447 - 2²⁷ = 6856680807719 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6856815023447) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3428407512723 + 3428407512724.

It is an arithmetic number, because the mean of its divisors is an integer number (3428407512724).

Almost surely, 2^{6856815025447} is an apocalyptic number.

6856815025447 is a deficient number, since it is larger than the sum of its proper divisors (1).

6856815025447 is an equidigital number, since it uses as much as digits as its factorization.

6856815025447 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64512000, while the sum is 61.

The spelling of 6856815025447 in words is "six trillion, eight hundred fifty-six billion, eight hundred fifteen million, twenty-five thousand, four hundred forty-seven".