51669616819 has 4 divisors (see below), whose sum is σ = 51670073944. Its totient is φ = 51669159696.

The previous prime is 51669616813. The next prime is 51669616829. The reversal of 51669616819 is 91861696615.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51669616819 is a prime.

It is a super-2 number, since 2×51669616819² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51669616813) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 78439 + ... + 330895.

It is an arithmetic number, because the mean of its divisors is an integer number (12917518486).

Almost surely, 2^51669616819 is an apocalyptic number.

51669616819 is a deficient number, since it is larger than the sum of its proper divisors (457125).

51669616819 is a wasteful number, since it uses less digits than its factorization.

51669616819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 457124.

The product of its digits is 4199040, while the sum is 58.

The spelling of 51669616819 in words is "fifty-one billion, six hundred sixty-nine million, six hundred sixteen thousand, eight hundred nineteen".