51665512207 has 4 divisors (see below), whose sum is σ = 51666095160. Its totient is φ = 51664929256.

The previous prime is 51665512193. The next prime is 51665512211. The reversal of 51665512207 is 70221556615.

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 not a de Polignac number, because 51665512207 - 2¹⁹ = 51664987919 is a prime.

It is a super-2 number, since 2×51665512207² (a number of 22 digits) contains 22 as substring.

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 51665512207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51665512247) 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, 127957 + ... + 345982.

It is an arithmetic number, because the mean of its divisors is an integer number (12916523790).

Almost surely, 2^51665512207 is an apocalyptic number.

51665512207 is a deficient number, since it is larger than the sum of its proper divisors (582953).

51665512207 is a wasteful number, since it uses less digits than its factorization.

51665512207 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 582952.

The product of its (nonzero) digits is 126000, while the sum is 40.

The spelling of 51665512207 in words is "fifty-one billion, six hundred sixty-five million, five hundred twelve thousand, two hundred seven".