51615486720 has 648 divisors, whose sum is σ = 211287258000. Its totient is φ = 11596677120.

The previous prime is 51615486691. The next prime is 51615486737. The reversal of 51615486720 is 2768451615.

51615486720 is a `hidden beast` number, since 5 + 1 + 615 + 4 + 8 + 6 + 7 + 20 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

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 71 ways as a sum of consecutive naturals, for example, 34432531 + ... + 34434029.

Almost surely, 2^51615486720 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 51615486720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (105643629000).

51615486720 is an abundant number, since it is smaller than the sum of its proper divisors (159671771280).

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

51615486720 is a wasteful number, since it uses less digits than its factorization.

51615486720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1601 (or 1577 counting only the distinct ones).

The product of its (nonzero) digits is 403200, while the sum is 45.

The spelling of 51615486720 in words is "fifty-one billion, six hundred fifteen million, four hundred eighty-six thousand, seven hundred twenty".