6921861460691 has 2 divisors, whose sum is σ = 6921861460692. Its totient is φ = 6921861460690.

The previous prime is 6921861460681. The next prime is 6921861460729. The reversal of 6921861460691 is 1960641681296.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6921861460691 - 2⁶ = 6921861460627 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 6921861460691.

It is not a weakly prime, because it can be changed into another prime (6921861460681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3460930730345 + 3460930730346.

It is an arithmetic number, because the mean of its divisors is an integer number (3460930730346).

Almost surely, 2^{6921861460691} is an apocalyptic number.

6921861460691 is a deficient number, since it is larger than the sum of its proper divisors (1).

6921861460691 is an equidigital number, since it uses as much as digits as its factorization.

6921861460691 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6718464, while the sum is 59.

The spelling of 6921861460691 in words is "six trillion, nine hundred twenty-one billion, eight hundred sixty-one million, four hundred sixty thousand, six hundred ninety-one".