51655550666665 has 16 divisors (see below), whose sum is σ = 68548137975936. Its totient is φ = 37053047548800.

The previous prime is 51655550666647. The next prime is 51655550666689. The reversal of 51655550666665 is 56666605555615.

It is a happy number.

It is not a de Polignac number, because 51655550666665 - 2⁵ = 51655550666633 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 51655550666665.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6432816741 + ... + 6432824770.

It is an arithmetic number, because the mean of its divisors is an integer number (4284258623496).

Almost surely, 2^{51655550666665} is an apocalyptic number.

51655550666665 is a gapful number since it is divisible by the number (55) formed by its first and last digit.

It is an amenable number.

51655550666665 is a deficient number, since it is larger than the sum of its proper divisors (16892587309271).

51655550666665 is a wasteful number, since it uses less digits than its factorization.

51655550666665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12865641600.

The product of its (nonzero) digits is 729000000, while the sum is 67.

The spelling of 51655550666665 in words is "fifty-one trillion, six hundred fifty-five billion, five hundred fifty million, six hundred sixty-six thousand, six hundred sixty-five".