6921861460729 has 2 divisors, whose sum is σ = 6921861460730. Its totient is φ = 6921861460728.

The previous prime is 6921861460691. The next prime is 6921861460781. The reversal of 6921861460729 is 9270641681296.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4872826672704 + 2049034788025 = 2207448^2 + 1431445^2 .

It is a cyclic number.

It is not a de Polignac number, because 6921861460729 - 2¹⁵ = 6921861427961 is a prime.

It is a super-2 number, since 2×6921861460729² (a number of 26 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (6921861460229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3460930730364 + 3460930730365.

It is an arithmetic number, because the mean of its divisors is an integer number (3460930730365).

Almost surely, 2^{6921861460729} is an apocalyptic number.

It is an amenable number.

6921861460729 is a deficient number, since it is larger than the sum of its proper divisors (1).

6921861460729 is an equidigital number, since it uses as much as digits as its factorization.

6921861460729 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15676416, while the sum is 61.

The spelling of 6921861460729 in words is "six trillion, nine hundred twenty-one billion, eight hundred sixty-one million, four hundred sixty thousand, seven hundred twenty-nine".