51605655601 has 4 divisors (see below), whose sum is σ = 51608895552. Its totient is φ = 51602415652.

The previous prime is 51605655599. The next prime is 51605655653. The reversal of 51605655601 is 10655650615.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 51605655601 - 2¹ = 51605655599 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51605655401) 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 3 ways as a sum of consecutive naturals, for example, 1595965 + ... + 1627978.

It is an arithmetic number, because the mean of its divisors is an integer number (12902223888).

Almost surely, 2^51605655601 is an apocalyptic number.

It is an amenable number.

51605655601 is a deficient number, since it is larger than the sum of its proper divisors (3239951).

51605655601 is a wasteful number, since it uses less digits than its factorization.

51605655601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3239950.

The product of its (nonzero) digits is 135000, while the sum is 40.

The spelling of 51605655601 in words is "fifty-one billion, six hundred five million, six hundred fifty-five thousand, six hundred one".