51408644 has 36 divisors (see below), whose sum is σ = 106116444. Its totient is φ = 21724416.

The previous prime is 51408589. The next prime is 51408649. The reversal of 51408644 is 44680415.

It can be written as a sum of positive squares in 2 ways, for example, as 22657600 + 28751044 = 4760^2 + 5362^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 51408644.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51408649) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12512 + ... + 16104.

It is an arithmetic number, because the mean of its divisors is an integer number (2947679).

Almost surely, 2^51408644 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 51408644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (53058222).

51408644 is an abundant number, since it is smaller than the sum of its proper divisors (54707800).

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

51408644 is a wasteful number, since it uses less digits than its factorization.

51408644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3684 (or 3675 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 32.

The square root of 51408644 is about 7169.9821478160. The cubic root of 51408644 is about 371.8308187419.

The spelling of 51408644 in words is "fifty-one million, four hundred eight thousand, six hundred forty-four".