51261560 has 128 divisors (see below), whose sum is σ = 139968000. Its totient is φ = 16525824.

The previous prime is 51261559. The next prime is 51261577. The reversal of 51261560 is 6516215.

It is a zygodrome in base 2.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 479027 + ... + 479133.

It is an arithmetic number, because the mean of its divisors is an integer number (1093500).

Almost surely, 2^51261560 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 51261560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (69984000).

51261560 is an abundant number, since it is smaller than the sum of its proper divisors (88706440).

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

51261560 is a wasteful number, since it uses less digits than its factorization.

51261560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213 (or 209 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 26.

The square root of 51261560 is about 7159.7178715366. The cubic root of 51261560 is about 371.4758680262.

Adding to 51261560 its reverse (6516215), we get a palindrome (57777775).

The spelling of 51261560 in words is "fifty-one million, two hundred sixty-one thousand, five hundred sixty".