6661155601 has 2 divisors, whose sum is σ = 6661155602. Its totient is φ = 6661155600.

The previous prime is 6661155583. The next prime is 6661155617. The reversal of 6661155601 is 1065511666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4667622400 + 1993533201 = 68320^2 + 44649^2 .

It is a cyclic number.

It is not a de Polignac number, because 6661155601 - 2⁹ = 6661155089 is a prime.

It is not a weakly prime, because it can be changed into another prime (6661155661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3330577800 + 3330577801.

It is an arithmetic number, because the mean of its divisors is an integer number (3330577801).

Almost surely, 2^6661155601 is an apocalyptic number.

It is an amenable number.

6661155601 is a deficient number, since it is larger than the sum of its proper divisors (1).

6661155601 is an equidigital number, since it uses as much as digits as its factorization.

6661155601 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32400, while the sum is 37.

The square root of 6661155601 is about 81615.9028682523. The cubic root of 6661155601 is about 1881.5533036564.

The spelling of 6661155601 in words is "six billion, six hundred sixty-one million, one hundred fifty-five thousand, six hundred one".