51018240 has 320 divisors, whose sum is σ = 203486976. Its totient is φ = 10616832.

The previous prime is 51018239. The next prime is 51018263. The reversal of 51018240 is 4281015.

It is a tau number, because it is divible by the number of its divisors (320).

It is a Harshad number since it is a multiple of its sum of digits (21).

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, 698844 + ... + 698916.

Almost surely, 2^51018240 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 51018240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (101743488).

51018240 is an abundant number, since it is smaller than the sum of its proper divisors (152468736).

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

51018240 is a wasteful number, since it uses less digits than its factorization.

51018240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 119 (or 103 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 21.

The square root of 51018240 is about 7142.7053698161. The cubic root of 51018240 is about 370.8871819571.

Adding to 51018240 its reverse (4281015), we get a palindrome (55299255).

The spelling of 51018240 in words is "fifty-one million, eighteen thousand, two hundred forty".