51660015561 has 48 divisors (see below), whose sum is σ = 94557959808. Its totient is φ = 26396409600.

The previous prime is 51660015523. The next prime is 51660015601. The reversal of 51660015561 is 16551006615.

It is not a de Polignac number, because 51660015561 - 2¹¹ = 51660013513 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (51660015521) 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 in 47 ways as a sum of consecutive naturals, for example, 568756 + ... + 653301.

It is an arithmetic number, because the mean of its divisors is an integer number (1969957496).

Almost surely, 2^51660015561 is an apocalyptic number.

It is an amenable number.

51660015561 is a deficient number, since it is larger than the sum of its proper divisors (42897944247).

51660015561 is a wasteful number, since it uses less digits than its factorization.

51660015561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1222142 (or 1222139 counting only the distinct ones).

The product of its (nonzero) digits is 27000, while the sum is 36.

The spelling of 51660015561 in words is "fifty-one billion, six hundred sixty million, fifteen thousand, five hundred sixty-one".