51661720335 has 16 divisors (see below), whose sum is σ = 83510906976. Its totient is φ = 27268866048.

The previous prime is 51661720321. The next prime is 51661720399. The reversal of 51661720335 is 53302716615.

It is a de Polignac number, because none of the positive numbers 2^k-51661720335 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 51661720293 and 51661720302.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 17751714 + ... + 17754623.

It is an arithmetic number, because the mean of its divisors is an integer number (5219431686).

Almost surely, 2^51661720335 is an apocalyptic number.

51661720335 is a deficient number, since it is larger than the sum of its proper divisors (31849186641).

51661720335 is a wasteful number, since it uses less digits than its factorization.

51661720335 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35506442.

The product of its (nonzero) digits is 113400, while the sum is 39.

The spelling of 51661720335 in words is "fifty-one billion, six hundred sixty-one million, seven hundred twenty thousand, three hundred thirty-five".