51216221952 has 432 divisors, whose sum is σ = 176319037440. Its totient is φ = 13989888000.

The previous prime is 51216221939. The next prime is 51216221993. The reversal of 51216221952 is 25912261215.

51216221952 is a `hidden beast` number, since 5 + 1 + 21 + 622 + 1 + 9 + 5 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 44496577 + ... + 44497727.

It is an arithmetic number, because the mean of its divisors is an integer number (408145920).

Almost surely, 2^51216221952 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 51216221952, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (88159518720).

51216221952 is an abundant number, since it is smaller than the sum of its proper divisors (125102815488).

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

51216221952 is a wasteful number, since it uses less digits than its factorization.

51216221952 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1300 (or 1283 counting only the distinct ones).

The product of its digits is 21600, while the sum is 36.

The spelling of 51216221952 in words is "fifty-one billion, two hundred sixteen million, two hundred twenty-one thousand, nine hundred fifty-two".