51116203681 has 4 divisors (see below), whose sum is σ = 51131589552. Its totient is φ = 51100817812.

The previous prime is 51116203661. The next prime is 51116203693. The reversal of 51116203681 is 18630261115.

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 51116203681 - 2¹⁵ = 51116170913 is a prime.

It is a super-2 number, since 2×51116203681² (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 (51116203661) 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, 7687951 + ... + 7694596.

It is an arithmetic number, because the mean of its divisors is an integer number (12782897388).

Almost surely, 2^51116203681 is an apocalyptic number.

It is an amenable number.

51116203681 is a deficient number, since it is larger than the sum of its proper divisors (15385871).

51116203681 is a wasteful number, since it uses less digits than its factorization.

51116203681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15385870.

The product of its (nonzero) digits is 8640, while the sum is 34.

Adding to 51116203681 its reverse (18630261115), we get a palindrome (69746464796).

The spelling of 51116203681 in words is "fifty-one billion, one hundred sixteen million, two hundred three thousand, six hundred eighty-one".