6781331601801 has 9 divisors (see below), whose sum is σ = 9795268042599. Its totient is φ = 4520882526336.

The previous prime is 6781331601787. The next prime is 6781331601823. The reversal of 6781331601801 is 1081061331876.

The square root of 6781331601801 is 2604099.

It is a perfect power (a square), and thus also a powerful number.

6781331601801 is a `hidden beast` number, since 6 + 7 + 8 + 1 + 3 + 31 + 601 + 8 + 0 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 3067139255625 + 3714192346176 = 1751325^2 + 1927224^2 .

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 6781331601801 - 2⁵ = 6781331601769 is a prime.

It is not an unprimeable number, because it can be changed into a prime (6781331601101) 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 in 8 ways as a sum of consecutive naturals, for example, 7378281 + ... + 8246313.

Almost surely, 2^{6781331601801} is an apocalyptic number.

6781331601801 is the 2604099-th square number.

6781331601801 is the 1302050-th centered octagonal number.

It is an amenable number.

6781331601801 is a deficient number, since it is larger than the sum of its proper divisors (3013936440798).

6781331601801 is an frugal number, since it uses more digits than its factorization.

6781331601801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1736072 (or 868036 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The spelling of 6781331601801 in words is "six trillion, seven hundred eighty-one billion, three hundred thirty-one million, six hundred one thousand, eight hundred one".