51111111100 has 54 divisors (see below), whose sum is σ = 129019059960. Its totient is φ = 17523807840.

The previous prime is 51111111071. The next prime is 51111111109. The reversal of 51111111100 is 111111115.

It is a super-2 number, since 2×51111111100² (a number of 22 digits) contains 22 as substring.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51111111109) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 5210520 + ... + 5220319.

Almost surely, 2^51111111100 is an apocalyptic number.

51111111100 is a gapful number since it is divisible by the number (50) formed by its first and last digit.

It is an amenable number.

51111111100 is an abundant number, since it is smaller than the sum of its proper divisors (77907948860).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51111111100 is a wasteful number, since it uses less digits than its factorization.

51111111100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10430867 (or 10430853 counting only the distinct ones).

The product of its (nonzero) digits is 5, while the sum is 13.

Adding to 51111111100 its reverse (111111115), we get a palindrome (51222222215).

The spelling of 51111111100 in words is "fifty-one billion, one hundred eleven million, one hundred eleven thousand, one hundred".