51245288640 has 840 divisors, whose sum is σ = 220681113120. Its totient is φ = 10690707456.

The previous prime is 51245288629. The next prime is 51245288663. The reversal of 51245288640 is 4688254215.

51245288640 is a `hidden beast` number, since 5 + 1 + 2 + 4 + 528 + 86 + 40 = 666.

51245288640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (840).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 575789716 + ... + 575789804.

Almost surely, 2^51245288640 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 51245288640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (110340556560).

51245288640 is an abundant number, since it is smaller than the sum of its proper divisors (169435824480).

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

51245288640 is an equidigital number, since it uses as much as digits as its factorization.

51245288640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 171 (or 119 counting only the distinct ones).

The product of its (nonzero) digits is 614400, while the sum is 45.

The spelling of 51245288640 in words is "fifty-one billion, two hundred forty-five million, two hundred eighty-eight thousand, six hundred forty".