51657402240 has 512 divisors, whose sum is σ = 198486288000. Its totient is φ = 12645826560.

The previous prime is 51657402233. The next prime is 51657402301. The reversal of 51657402240 is 4220475615.

It is a happy number.

51657402240 is a `hidden beast` number, since 5 + 1 + 6 + 5 + 7 + 402 + 240 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 51657402195 and 51657402204.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 12042016 + ... + 12046304.

Almost surely, 2^51657402240 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 51657402240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (99243144000).

51657402240 is an abundant number, since it is smaller than the sum of its proper divisors (146828885760).

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

51657402240 is a wasteful number, since it uses less digits than its factorization.

51657402240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4375 (or 4357 counting only the distinct ones).

The product of its (nonzero) digits is 67200, while the sum is 36.

Adding to 51657402240 its reverse (4220475615), we get a palindrome (55877877855).

The spelling of 51657402240 in words is "fifty-one billion, six hundred fifty-seven million, four hundred two thousand, two hundred forty".