51051840 has 224 divisors, whose sum is σ = 189609984. Its totient is φ = 11397120.

The previous prime is 51051839. The next prime is 51051851. The reversal of 51051840 is 4815015.

It is a tau number, because it is divible by the number of its divisors (224).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 51051840.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 477067 + ... + 477173.

Almost surely, 2^51051840 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 51051840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (94804992).

51051840 is an abundant number, since it is smaller than the sum of its proper divisors (138558144).

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

51051840 is a wasteful number, since it uses less digits than its factorization.

51051840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 205 (or 195 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 24.

The square root of 51051840 is about 7145.0570326625. The cubic root of 51051840 is about 370.9685847037.

Adding to 51051840 its reverse (4815015), we get a palindrome (55866855).

The spelling of 51051840 in words is "fifty-one million, fifty-one thousand, eight hundred forty".