51312820 has 48 divisors (see below), whose sum is σ = 116903808. Its totient is φ = 18806400.

The previous prime is 51312809. The next prime is 51312829. The reversal of 51312820 is 2821315.

It is a junction number, because it is equal to n+sod(n) for n = 51312791 and 51312800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51312829) 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, 38607 + ... + 39913.

It is an arithmetic number, because the mean of its divisors is an integer number (2435496).

Almost surely, 2^51312820 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 51312820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (58451904).

51312820 is an abundant number, since it is smaller than the sum of its proper divisors (65590988).

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

51312820 is a wasteful number, since it uses less digits than its factorization.

51312820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1480 (or 1478 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 51312820 is about 7163.2967270664. The cubic root of 51312820 is about 371.5996482976.

The spelling of 51312820 in words is "fifty-one million, three hundred twelve thousand, eight hundred twenty".