51111840 has 96 divisors (see below), whose sum is σ = 173408256. Its totient is φ = 12579840.

The previous prime is 51111787. The next prime is 51111857. The reversal of 51111840 is 4811115.

It is a happy number.

51111840 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-2 number, since 2×51111840² = 5224840376371200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 2145 + ... + 10335.

It is an arithmetic number, because the mean of its divisors is an integer number (1806336).

Almost surely, 2^51111840 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51111840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (86704128).

51111840 is an abundant number, since it is smaller than the sum of its proper divisors (122296416).

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

51111840 is a wasteful number, since it uses less digits than its factorization.

51111840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8222 (or 8214 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 21.

The square root of 51111840 is about 7149.2545065902. The cubic root of 51111840 is about 371.1138579590.

Adding to 51111840 its reverse (4811115), we get a palindrome (55922955).

The spelling of 51111840 in words is "fifty-one million, one hundred eleven thousand, eight hundred forty".