51351440 has 80 divisors (see below), whose sum is σ = 137884032. Its totient is φ = 17421312.

The previous prime is 51351439. The next prime is 51351451. The reversal of 51351440 is 4415315.

51351440 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 59492 + ... + 60348.

Almost surely, 2^51351440 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 51351440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (68942016).

51351440 is an abundant number, since it is smaller than the sum of its proper divisors (86532592).

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

51351440 is a wasteful number, since it uses less digits than its factorization.

51351440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 984 (or 978 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 23.

The square root of 51351440 is about 7165.9919062193. The cubic root of 51351440 is about 371.6928516433.

Adding to 51351440 its reverse (4415315), we get a palindrome (55766755).

The spelling of 51351440 in words is "fifty-one million, three hundred fifty-one thousand, four hundred forty".