51550000 has 60 divisors (see below), whose sum is σ = 124960752. Its totient is φ = 20600000.

The previous prime is 51549959. The next prime is 51550007. The reversal of 51550000 is 5515.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is not an unprimeable number, because it can be changed into a prime (51550007) 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 11 ways as a sum of consecutive naturals, for example, 49485 + ... + 50515.

Almost surely, 2^51550000 is an apocalyptic number.

51550000 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 51550000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (62480376).

51550000 is an abundant number, since it is smaller than the sum of its proper divisors (73410752).

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

51550000 is an equidigital number, since it uses as much as digits as its factorization.

51550000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1064 (or 1038 counting only the distinct ones).

The product of its (nonzero) digits is 125, while the sum is 16.

The square root of 51550000 is about 7179.8328671356. The cubic root of 51550000 is about 372.1713089278.

Adding to 51550000 its reverse (5515), we get a palindrome (51555515).

The spelling of 51550000 in words is "fifty-one million, five hundred fifty thousand".