6675555781 has 2 divisors, whose sum is σ = 6675555782. Its totient is φ = 6675555780.

The previous prime is 6675555739. The next prime is 6675555793. The reversal of 6675555781 is 1875555766.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6247479681 + 428076100 = 79041^2 + 20690^2 .

It is a cyclic number.

It is not a de Polignac number, because 6675555781 - 2¹³ = 6675547589 is a prime.

It is a super-3 number, since 3×6675555781³ (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 (6675555721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3337777890 + 3337777891.

It is an arithmetic number, because the mean of its divisors is an integer number (3337777891).

Almost surely, 2^6675555781 is an apocalyptic number.

It is an amenable number.

6675555781 is a deficient number, since it is larger than the sum of its proper divisors (1).

6675555781 is an equidigital number, since it uses as much as digits as its factorization.

6675555781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8820000, while the sum is 55.

The square root of 6675555781 is about 81704.0744455257. The cubic root of 6675555781 is about 1882.9081839363.

The spelling of 6675555781 in words is "six billion, six hundred seventy-five million, five hundred fifty-five thousand, seven hundred eighty-one".