51128940 has 24 divisors (see below), whose sum is σ = 143161200. Its totient is φ = 13634368.

The previous prime is 51128929. The next prime is 51128947. The reversal of 51128940 is 4982115.

It is a happy number.

It is a super-2 number, since 2×51128940² = 5228337011047200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 51128898 and 51128907.

It is not an unprimeable number, because it can be changed into a prime (51128947) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 426015 + ... + 426134.

It is an arithmetic number, because the mean of its divisors is an integer number (5965050).

Almost surely, 2^51128940 is an apocalyptic number.

It is an amenable number.

51128940 is an abundant number, since it is smaller than the sum of its proper divisors (92032260).

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

51128940 is a wasteful number, since it uses less digits than its factorization.

51128940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 852161 (or 852159 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 30.

The square root of 51128940 is about 7150.4503354684. The cubic root of 51128940 is about 371.1552400170.

The spelling of 51128940 in words is "fifty-one million, one hundred twenty-eight thousand, nine hundred forty".