51012240 has 80 divisors (see below), whose sum is σ = 167453568. Its totient is φ = 12802048.

The previous prime is 51012211. The next prime is 51012253. The reversal of 51012240 is 4221015.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2172 + ... + 10331.

Almost surely, 2^51012240 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 51012240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (83726784).

51012240 is an abundant number, since it is smaller than the sum of its proper divisors (116441328).

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

51012240 is a wasteful number, since it uses less digits than its factorization.

51012240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12536 (or 12530 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 15.

The square root of 51012240 is about 7142.2853485422. The cubic root of 51012240 is about 370.8726419917.

Adding to 51012240 its reverse (4221015), we get a palindrome (55233255).

The spelling of 51012240 in words is "fifty-one million, twelve thousand, two hundred forty".