51215424 has 168 divisors, whose sum is σ = 157203648. Its totient is φ = 14622720.

The previous prime is 51215419. The next prime is 51215429. The reversal of 51215424 is 42451215.

It is an interprime number because it is at equal distance from previous prime (51215419) and next prime (51215429).

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

It is a junction number, because it is equal to n+sod(n) for n = 51215394 and 51215403.

It is not an unprimeable number, because it can be changed into a prime (51215429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 721309 + ... + 721379.

It is an arithmetic number, because the mean of its divisors is an integer number (935736).

Almost surely, 2^51215424 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 51215424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (78601824).

51215424 is an abundant number, since it is smaller than the sum of its proper divisors (105988224).

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

51215424 is a wasteful number, since it uses less digits than its factorization.

51215424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133 (or 106 counting only the distinct ones).

The product of its digits is 1600, while the sum is 24.

The square root of 51215424 is about 7156.4952316060. The cubic root of 51215424 is about 371.3643903757.

Adding to 51215424 its reverse (42451215), we get a palindrome (93666639).

The spelling of 51215424 in words is "fifty-one million, two hundred fifteen thousand, four hundred twenty-four".