51212140 has 96 divisors (see below), whose sum is σ = 129153024. Its totient is φ = 16692480.

The previous prime is 51212137. The next prime is 51212159. The reversal of 51212140 is 4121215.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 282850 + ... + 283030.

It is an arithmetic number, because the mean of its divisors is an integer number (1345344).

Almost surely, 2^51212140 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51212140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (64576512).

51212140 is an abundant number, since it is smaller than the sum of its proper divisors (77940884).

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

51212140 is a wasteful number, since it uses less digits than its factorization.

51212140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 287 (or 285 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 16.

The square root of 51212140 is about 7156.2657860088. The cubic root of 51212140 is about 371.3564527491.

Adding to 51212140 its reverse (4121215), we get a palindrome (55333355).

The spelling of 51212140 in words is "fifty-one million, two hundred twelve thousand, one hundred forty".