6691485421 has 2 divisors, whose sum is σ = 6691485422. Its totient is φ = 6691485420.

The previous prime is 6691485397. The next prime is 6691485467. The reversal of 6691485421 is 1245841966.

It is a happy number.

It is an a-pointer prime, because the next prime (6691485467) can be obtained adding 6691485421 to its sum of digits (46).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6689440521 + 2044900 = 81789^2 + 1430^2 .

It is a cyclic number.

It is not a de Polignac number, because 6691485421 - 2⁵ = 6691485389 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6691425421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3345742710 + 3345742711.

It is an arithmetic number, because the mean of its divisors is an integer number (3345742711).

Almost surely, 2^6691485421 is an apocalyptic number.

It is an amenable number.

6691485421 is a deficient number, since it is larger than the sum of its proper divisors (1).

6691485421 is an equidigital number, since it uses as much as digits as its factorization.

6691485421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 414720, while the sum is 46.

The square root of 6691485421 is about 81801.5001146067. The cubic root of 6691485421 is about 1884.4046996910.

The spelling of 6691485421 in words is "six billion, six hundred ninety-one million, four hundred eighty-five thousand, four hundred twenty-one".