51249440 has 96 divisors (see below), whose sum is σ = 135825984. Its totient is φ = 18109440.

The previous prime is 51249391. The next prime is 51249503. The reversal of 51249440 is 4494215.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 64727 + ... + 65513.

It is an arithmetic number, because the mean of its divisors is an integer number (1414854).

Almost surely, 2^51249440 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 51249440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (67912992).

51249440 is an abundant number, since it is smaller than the sum of its proper divisors (84576544).

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

51249440 is a wasteful number, since it uses less digits than its factorization.

51249440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 850 (or 842 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 29.

The square root of 51249440 is about 7158.8714194348. The cubic root of 51249440 is about 371.4465891513.

The spelling of 51249440 in words is "fifty-one million, two hundred forty-nine thousand, four hundred forty".