51550320 has 80 divisors (see below), whose sum is σ = 160525440. Its totient is φ = 13684992.

The previous prime is 51550319. The next prime is 51550333. The reversal of 51550320 is 2305515.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 82971 + ... + 83589.

It is an arithmetic number, because the mean of its divisors is an integer number (2006568).

Almost surely, 2^51550320 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 51550320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (80262720).

51550320 is an abundant number, since it is smaller than the sum of its proper divisors (108975120).

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

51550320 is a wasteful number, since it uses less digits than its factorization.

51550320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 982 (or 976 counting only the distinct ones).

The product of its (nonzero) digits is 750, while the sum is 21.

The square root of 51550320 is about 7179.8551517423. The cubic root of 51550320 is about 372.1720790188.

Adding to 51550320 its reverse (2305515), we get a palindrome (53855835).

The spelling of 51550320 in words is "fifty-one million, five hundred fifty thousand, three hundred twenty".