51399333216 has 1152 divisors, whose sum is σ = 206979494400. Its totient is φ = 12227604480.

The previous prime is 51399333203. The next prime is 51399333239. The reversal of 51399333216 is 61233399315.

51399333216 is a `hidden beast` number, since 5 + 13 + 99 + 333 + 216 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 327384210 + ... + 327384366.

It is an arithmetic number, because the mean of its divisors is an integer number (179669700).

Almost surely, 2^51399333216 is an apocalyptic number.

51399333216 is a gapful number since it is divisible by the number (56) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51399333216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (103489747200).

51399333216 is an abundant number, since it is smaller than the sum of its proper divisors (155580161184).

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

51399333216 is a wasteful number, since it uses less digits than its factorization.

51399333216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 257 (or 236 counting only the distinct ones).

The product of its digits is 393660, while the sum is 45.

The spelling of 51399333216 in words is "fifty-one billion, three hundred ninety-nine million, three hundred thirty-three thousand, two hundred sixteen".