51388320 has 96 divisors (see below), whose sum is σ = 163175040. Its totient is φ = 13593600.

The previous prime is 51388307. The next prime is 51388327. The reversal of 51388320 is 2388315.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (51388327) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 72126 + ... + 72834.

It is an arithmetic number, because the mean of its divisors is an integer number (1699740).

Almost surely, 2^51388320 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 51388320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (81587520).

51388320 is an abundant number, since it is smaller than the sum of its proper divisors (111786720).

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

51388320 is a wasteful number, since it uses less digits than its factorization.

51388320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 878 (or 870 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 51388320 is about 7168.5647098983. The cubic root of 51388320 is about 371.7818121608.

The spelling of 51388320 in words is "fifty-one million, three hundred eighty-eight thousand, three hundred twenty".