51393821544 has 192 divisors, whose sum is σ = 163633579200. Its totient is φ = 14981054976.

The previous prime is 51393821543. The next prime is 51393821581. The reversal of 51393821544 is 44512839315.

51393821544 is a `hidden beast` number, since 5 + 1 + 393 + 8 + 215 + 44 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 51393821544.

It is not an unprimeable number, because it can be changed into a prime (51393821543) 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, 426652 + ... + 533684.

It is an arithmetic number, because the mean of its divisors is an integer number (852258225).

Almost surely, 2^51393821544 is an apocalyptic number.

51393821544 is a gapful number since it is divisible by the number (54) 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 51393821544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (81816789600).

51393821544 is an abundant number, since it is smaller than the sum of its proper divisors (112239757656).

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

51393821544 is a wasteful number, since it uses less digits than its factorization.

51393821544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107086 (or 107070 counting only the distinct ones).

The product of its digits is 518400, while the sum is 45.

The spelling of 51393821544 in words is "fifty-one billion, three hundred ninety-three million, eight hundred twenty-one thousand, five hundred forty-four".