51866451202385 has 4 divisors (see below), whose sum is σ = 62239741442868. Its totient is φ = 41493160961904.

The previous prime is 51866451202351. The next prime is 51866451202417. The reversal of 51866451202385 is 58320215466815.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 39784758090256 + 12081693112129 = 6307516^2 + 3475873^2 .

It is a cyclic number.

It is not a de Polignac number, because 51866451202385 - 2¹⁶ = 51866451136849 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 51866451202385.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5186645120234 + ... + 5186645120243.

It is an arithmetic number, because the mean of its divisors is an integer number (15559935360717).

Almost surely, 2^{51866451202385} is an apocalyptic number.

It is an amenable number.

51866451202385 is a deficient number, since it is larger than the sum of its proper divisors (10373290240483).

51866451202385 is a wasteful number, since it uses less digits than its factorization.

51866451202385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10373290240482.

The product of its (nonzero) digits is 13824000, while the sum is 56.

The spelling of 51866451202385 in words is "fifty-one trillion, eight hundred sixty-six billion, four hundred fifty-one million, two hundred two thousand, three hundred eighty-five".