51225440 has 48 divisors (see below), whose sum is σ = 138311712. Its totient is φ = 17562624.

The previous prime is 51225431. The next prime is 51225467. The reversal of 51225440 is 4452215.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 21749 + ... + 23988.

It is an arithmetic number, because the mean of its divisors is an integer number (2881494).

Almost surely, 2^51225440 is an apocalyptic number.

It is an amenable number.

51225440 is an abundant number, since it is smaller than the sum of its proper divisors (87086272).

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

51225440 is a wasteful number, since it uses less digits than its factorization.

51225440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45759 (or 45751 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 23.

The square root of 51225440 is about 7157.1949812758. The cubic root of 51225440 is about 371.3885975578.

Adding to 51225440 its reverse (4452215), we get a palindrome (55677655).

It can be divided in two parts, 512 and 25440, that added together give a palindrome (25952).

The spelling of 51225440 in words is "fifty-one million, two hundred twenty-five thousand, four hundred forty".