51612320 has 48 divisors (see below), whose sum is σ = 122744160. Its totient is φ = 20507904.

The previous prime is 51612307. The next prime is 51612329. The reversal of 51612320 is 2321615.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 51612292 and 51612301.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51612329) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25091 + ... + 27069.

It is an arithmetic number, because the mean of its divisors is an integer number (2557170).

Almost surely, 2^51612320 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 51612320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (61372080).

51612320 is an abundant number, since it is smaller than the sum of its proper divisors (71131840).

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

51612320 is a wasteful number, since it uses less digits than its factorization.

51612320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2157 (or 2149 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 51612320 is about 7184.1714901581. The cubic root of 51612320 is about 372.3212240637.

Adding to 51612320 its reverse (2321615), we get a palindrome (53933935).

The spelling of 51612320 in words is "fifty-one million, six hundred twelve thousand, three hundred twenty".