6767661001581 has 48 divisors (see below), whose sum is σ = 10010541800688. Its totient is φ = 4404425932800.

The previous prime is 6767661001537. The next prime is 6767661001601. The reversal of 6767661001581 is 1851001667676.

6767661001581 is a `hidden beast` number, since 6 + 7 + 6 + 7 + 6 + 610 + 0 + 15 + 8 + 1 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 792892298025 + 5974768703556 = 890445^2 + 2444334^2 .

It is a de Polignac number, because none of the positive numbers 2^k-6767661001581 is a prime.

It is a super-2 number, since 2×6767661001581² (a number of 26 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6767661001501) 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 47 ways as a sum of consecutive naturals, for example, 494669061 + ... + 494682741.

It is an arithmetic number, because the mean of its divisors is an integer number (208552954181).

Almost surely, 2^{6767661001581} is an apocalyptic number.

6767661001581 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

It is an amenable number.

6767661001581 is a deficient number, since it is larger than the sum of its proper divisors (3242880799107).

6767661001581 is a wasteful number, since it uses less digits than its factorization.

6767661001581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20462 (or 20459 counting only the distinct ones).

The product of its (nonzero) digits is 2540160, while the sum is 54.

The spelling of 6767661001581 in words is "six trillion, seven hundred sixty-seven billion, six hundred sixty-one million, one thousand, five hundred eighty-one".