51212200 has 48 divisors (see below), whose sum is σ = 128233980. Its totient is φ = 18908160.

The previous prime is 51212197. The next prime is 51212207. The reversal of 51212200 is 221215.

It can be written as a sum of positive squares in 6 ways, for example, as 2965284 + 48246916 = 1722^2 + 6946^2 .

It is a Harshad number since it is a multiple of its sum of digits (13).

It is not an unprimeable number, because it can be changed into a prime (51212207) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7249 + ... + 12448.

Almost surely, 2^51212200 is an apocalyptic number.

51212200 is a gapful number since it is divisible by the number (50) formed by its first and last digit.

It is an amenable number.

51212200 is an abundant number, since it is smaller than the sum of its proper divisors (77021780).

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

51212200 is a wasteful number, since it uses less digits than its factorization.

51212200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19726 (or 19717 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 13.

The square root of 51212200 is about 7156.2699781381. The cubic root of 51212200 is about 371.3565977758.

Adding to 51212200 its reverse (221215), we get a palindrome (51433415).

The spelling of 51212200 in words is "fifty-one million, two hundred twelve thousand, two hundred".