6661051561 has 16 divisors (see below), whose sum is σ = 7035678720. Its totient is φ = 6297762960.

The previous prime is 6661051549. The next prime is 6661051583. The reversal of 6661051561 is 1651501666.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6661051561 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 6661051561.

It is not an unprimeable number, because it can be changed into a prime (6661051541) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 286956 + ... + 309298.

It is an arithmetic number, because the mean of its divisors is an integer number (439729920).

Almost surely, 2^6661051561 is an apocalyptic number.

It is an amenable number.

6661051561 is a deficient number, since it is larger than the sum of its proper divisors (374627159).

6661051561 is a wasteful number, since it uses less digits than its factorization.

6661051561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22596.

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

The square root of 6661051561 is about 81615.2654899805. The cubic root of 6661051561 is about 1881.5435076672.

The spelling of 6661051561 in words is "six billion, six hundred sixty-one million, fifty-one thousand, five hundred sixty-one".