51406720 has 64 divisors (see below), whose sum is σ = 125582400. Its totient is φ = 20113408.

The previous prime is 51406717. The next prime is 51406721. The reversal of 51406720 is 2760415.

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-3 number, since 3×51406720³ (a number of 24 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51406721) 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, 29226 + ... + 30934.

It is an arithmetic number, because the mean of its divisors is an integer number (1962225).

Almost surely, 2^51406720 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 51406720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (62791200).

51406720 is an abundant number, since it is smaller than the sum of its proper divisors (74175680).

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

51406720 is a wasteful number, since it uses less digits than its factorization.

51406720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1775 (or 1763 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 25.

The square root of 51406720 is about 7169.8479760731. The cubic root of 51406720 is about 371.8261800187.

The spelling of 51406720 in words is "fifty-one million, four hundred six thousand, seven hundred twenty".