51111122121 has 64 divisors (see below), whose sum is σ = 81674419200. Its totient is φ = 31485428352.

The previous prime is 51111122107. The next prime is 51111122137. The reversal of 51111122121 is 12122111115.

It is a happy number.

51111122121 is a `hidden beast` number, since 511 + 1 + 11 + 22 + 121 = 666.

It is not a de Polignac number, because 51111122121 - 2¹⁴ = 51111105737 is a prime.

It is a super-2 number, since 2×51111122121² (a number of 22 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 51111122094 and 51111122103.

It is not an unprimeable number, because it can be changed into a prime (51111122141) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 22785826 + ... + 22788068.

It is an arithmetic number, because the mean of its divisors is an integer number (1276162800).

Almost surely, 2^51111122121 is an apocalyptic number.

It is an amenable number.

51111122121 is a deficient number, since it is larger than the sum of its proper divisors (30563297079).

51111122121 is a wasteful number, since it uses less digits than its factorization.

51111122121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3347 (or 3341 counting only the distinct ones).

The product of its digits is 40, while the sum is 18.

Adding to 51111122121 its reverse (12122111115), we get a palindrome (63233233236).

The spelling of 51111122121 in words is "fifty-one billion, one hundred eleven million, one hundred twenty-two thousand, one hundred twenty-one".