6821256954191 has 2 divisors, whose sum is σ = 6821256954192. Its totient is φ = 6821256954190.

The previous prime is 6821256954167. The next prime is 6821256954283. The reversal of 6821256954191 is 1914596521286.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6821256954191 - 2¹⁰ = 6821256953167 is a prime.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 6821256954191.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6821256954151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3410628477095 + 3410628477096.

It is an arithmetic number, because the mean of its divisors is an integer number (3410628477096).

Almost surely, 2^{6821256954191} is an apocalyptic number.

6821256954191 is a deficient number, since it is larger than the sum of its proper divisors (1).

6821256954191 is an equidigital number, since it uses as much as digits as its factorization.

6821256954191 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9331200, while the sum is 59.

The spelling of 6821256954191 in words is "six trillion, eight hundred twenty-one billion, two hundred fifty-six million, nine hundred fifty-four thousand, one hundred ninety-one".