51640560 has 120 divisors (see below), whose sum is σ = 183671280. Its totient is φ = 12957696.

The previous prime is 51640553. The next prime is 51640571. The reversal of 51640560 is 6504615.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (120).

It is a super-3 number, since 3×51640560³ (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 an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10131 + ... + 14349.

It is an arithmetic number, because the mean of its divisors is an integer number (1530594).

Almost surely, 2^51640560 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 51640560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (91835640).

51640560 is an abundant number, since it is smaller than the sum of its proper divisors (132030720).

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

51640560 is a wasteful number, since it uses less digits than its factorization.

51640560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4255 (or 4246 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The square root of 51640560 is about 7186.1366533068. The cubic root of 51640560 is about 372.3891176357.

The spelling of 51640560 in words is "fifty-one million, six hundred forty thousand, five hundred sixty".