51212500 has 72 divisors (see below), whose sum is σ = 119101752. Its totient is φ = 19200000.

The previous prime is 51212479. The next prime is 51212503. The reversal of 51212500 is 521215.

It can be written as a sum of positive squares in 12 ways, for example, as 46212804 + 4999696 = 6798^2 + 2236^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51212503) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 212380 + ... + 212620.

It is an arithmetic number, because the mean of its divisors is an integer number (1654191).

Almost surely, 2^51212500 is an apocalyptic number.

51212500 is a gapful number since it is divisible by the number (50) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51212500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (59550876).

51212500 is an abundant number, since it is smaller than the sum of its proper divisors (67889252).

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

51212500 is a wasteful number, since it uses less digits than its factorization.

51212500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 287 (or 265 counting only the distinct ones).

The product of its (nonzero) digits is 100, while the sum is 16.

The square root of 51212500 is about 7156.2909387475. The cubic root of 51212500 is about 371.3573229075.

Adding to 51212500 its reverse (521215), we get a palindrome (51733715).

The spelling of 51212500 in words is "fifty-one million, two hundred twelve thousand, five hundred".