51215580 has 144 divisors (see below), whose sum is σ = 171531360. Its totient is φ = 12289536.

The previous prime is 51215573. The next prime is 51215581. The reversal of 51215580 is 8551215.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51215581) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 100366 + ... + 100874.

It is an arithmetic number, because the mean of its divisors is an integer number (1191190).

Almost surely, 2^51215580 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 51215580, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (85765680).

51215580 is an abundant number, since it is smaller than the sum of its proper divisors (120315780).

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

51215580 is a wasteful number, since it uses less digits than its factorization.

51215580 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 580 (or 575 counting only the distinct ones).

The product of its (nonzero) digits is 2000, while the sum is 27.

The square root of 51215580 is about 7156.5061307876. The cubic root of 51215580 is about 371.3647674287.

Adding to 51215580 its reverse (8551215), we get a palindrome (59766795).

It can be divided in two parts, 5121 and 5580, that added together give a palindrome (10701).

The spelling of 51215580 in words is "fifty-one million, two hundred fifteen thousand, five hundred eighty".