51451540 has 48 divisors (see below), whose sum is σ = 125596800. Its totient is φ = 17338752.

The previous prime is 51451513. The next prime is 51451541. The reversal of 51451540 is 4515415.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51451541) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5146 + ... + 11374.

It is an arithmetic number, because the mean of its divisors is an integer number (2616600).

Almost surely, 2^51451540 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 51451540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (62798400).

51451540 is an abundant number, since it is smaller than the sum of its proper divisors (74145260).

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

51451540 is a wasteful number, since it uses less digits than its factorization.

51451540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6304 (or 6302 counting only the distinct ones).

The product of its (nonzero) digits is 2000, while the sum is 25.

The square root of 51451540 is about 7172.9728843765. The cubic root of 51451540 is about 371.9342100481.

Adding to 51451540 its reverse (4515415), we get a palindrome (55966955).

The spelling of 51451540 in words is "fifty-one million, four hundred fifty-one thousand, five hundred forty".