51221544960 has 480 divisors, whose sum is σ = 173563391232. Its totient is φ = 12881756160.

The previous prime is 51221544947. The next prime is 51221545009. The reversal of 51221544960 is 6944512215.

It is a tau number, because it is divible by the number of its divisors (480).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 391004095 + ... + 391004225.

Almost surely, 2^51221544960 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 51221544960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (86781695616).

51221544960 is an abundant number, since it is smaller than the sum of its proper divisors (122341846272).

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

51221544960 is a wasteful number, since it uses less digits than its factorization.

51221544960 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 247 (or 221 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 39.

The spelling of 51221544960 in words is "fifty-one billion, two hundred twenty-one million, five hundred forty-four thousand, nine hundred sixty".