51398208 has 168 divisors, whose sum is σ = 162260280. Its totient is φ = 15482880.

The previous prime is 51398203. The next prime is 51398209. The reversal of 51398208 is 80289315.

It can be written as a sum of positive squares in 4 ways, for example, as 2286144 + 49112064 = 1512^2 + 7008^2 .

It is a super-2 number, since 2×51398208² = 5283551571222528, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (51398203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 283878 + ... + 284058.

It is an arithmetic number, because the mean of its divisors is an integer number (965835).

Almost surely, 2^51398208 is an apocalyptic number.

51398208 is a gapful number since it is divisible by the number (58) 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 51398208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (81130140).

51398208 is an abundant number, since it is smaller than the sum of its proper divisors (110862072).

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

51398208 is a wasteful number, since it uses less digits than its factorization.

51398208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 245 (or 232 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The square root of 51398208 is about 7169.2543545337. The cubic root of 51398208 is about 371.8056563780.

The spelling of 51398208 in words is "fifty-one million, three hundred ninety-eight thousand, two hundred eight".