51456398994 has 768 divisors, whose sum is σ = 167563468800. Its totient is φ = 10973491200.

The previous prime is 51456398993. The next prime is 51456399037. The reversal of 51456398994 is 49989365415.

51456398994 is a `hidden beast` number, since 5 + 1 + 456 + 3 + 98 + 9 + 94 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (51456398993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 704882142 + ... + 704882214.

It is an arithmetic number, because the mean of its divisors is an integer number (218181600).

Almost surely, 2^51456398994 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51456398994, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (83781734400).

51456398994 is an abundant number, since it is smaller than the sum of its proper divisors (116107069806).

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

51456398994 is a wasteful number, since it uses less digits than its factorization.

51456398994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 231 (or 228 counting only the distinct ones).

The product of its digits is 41990400, while the sum is 63.

The spelling of 51456398994 in words is "fifty-one billion, four hundred fifty-six million, three hundred ninety-eight thousand, nine hundred ninety-four".