6601425581 has 2 divisors, whose sum is σ = 6601425582. Its totient is φ = 6601425580.

The previous prime is 6601425577. The next prime is 6601425599. The reversal of 6601425581 is 1855241066.

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., 4571112100 + 2030313481 = 67610^2 + 45059^2 .

It is a cyclic number.

It is not a de Polignac number, because 6601425581 - 2² = 6601425577 is a prime.

It is a super-3 number, since 3×6601425581³ (a number of 30 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6601425511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3300712790 + 3300712791.

It is an arithmetic number, because the mean of its divisors is an integer number (3300712791).

Almost surely, 2^6601425581 is an apocalyptic number.

It is an amenable number.

6601425581 is a deficient number, since it is larger than the sum of its proper divisors (1).

6601425581 is an equidigital number, since it uses as much as digits as its factorization.

6601425581 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 57600, while the sum is 38.

The square root of 6601425581 is about 81249.1574171696. The cubic root of 6601425581 is about 1875.9124998211.

It can be divided in two parts, 660 and 1425581, that added together give a palindrome (1426241).

The spelling of 6601425581 in words is "six billion, six hundred one million, four hundred twenty-five thousand, five hundred eighty-one".