51721460 has 72 divisors (see below), whose sum is σ = 127983240. Its totient is φ = 17504256.

The previous prime is 51721447. The next prime is 51721487. The reversal of 51721460 is 6412715.

51721460 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 2328676 + 49392784 = 1526^2 + 7028^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 86924 + ... + 87516.

It is an arithmetic number, because the mean of its divisors is an integer number (1777545).

Almost surely, 2^51721460 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 51721460, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (63991620).

51721460 is an abundant number, since it is smaller than the sum of its proper divisors (76261780).

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

51721460 is a wasteful number, since it uses less digits than its factorization.

51721460 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 705 (or 696 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 26.

The square root of 51721460 is about 7191.7633442710. The cubic root of 51721460 is about 372.5834775301.

The spelling of 51721460 in words is "fifty-one million, seven hundred twenty-one thousand, four hundred sixty".