51109400 has 48 divisors (see below), whose sum is σ = 119307840. Its totient is φ = 20361600.

The previous prime is 51109393. The next prime is 51109403. The reversal of 51109400 is 490115.

51109400 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×51109400² = 5224341536720000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51109403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 83897 + ... + 84503.

It is an arithmetic number, because the mean of its divisors is an integer number (2485580).

Almost surely, 2^51109400 is an apocalyptic number.

51109400 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 51109400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (59653920).

51109400 is an abundant number, since it is smaller than the sum of its proper divisors (68198440).

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

51109400 is a wasteful number, since it uses less digits than its factorization.

51109400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1044 (or 1035 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 20.

The square root of 51109400 is about 7149.0838573904. The cubic root of 51109400 is about 371.1079523983.

Adding to 51109400 its reverse (490115), we get a palindrome (51599515).

The spelling of 51109400 in words is "fifty-one million, one hundred nine thousand, four hundred".