51465840 has 80 divisors (see below), whose sum is σ = 163287168. Its totient is φ = 13402368.

The previous prime is 51465833. The next prime is 51465847. The reversal of 51465840 is 4856415.

It is an interprime number because it is at equal distance from previous prime (51465833) and next prime (51465847).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51465847) 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 15 ways as a sum of consecutive naturals, for example, 7827 + ... + 12813.

Almost surely, 2^51465840 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 51465840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (81643584).

51465840 is an abundant number, since it is smaller than the sum of its proper divisors (111821328).

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

51465840 is a wasteful number, since it uses less digits than its factorization.

51465840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5046 (or 5040 counting only the distinct ones).

The product of its (nonzero) digits is 19200, while the sum is 33.

The square root of 51465840 is about 7173.9696124252. The cubic root of 51465840 is about 371.9686642584.

The spelling of 51465840 in words is "fifty-one million, four hundred sixty-five thousand, eight hundred forty".