6405137856 has 252 divisors, whose sum is σ = 20624807112. Its totient is φ = 1970002944.

The previous prime is 6405137831. The next prime is 6405137857. The reversal of 6405137856 is 6587315046.

6405137856 is a `hidden beast` number, since 64 + 0 + 513 + 78 + 5 + 6 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6405137857) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 2627070 + ... + 2629506.

Almost surely, 2^6405137856 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 6405137856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10312403556).

6405137856 is an abundant number, since it is smaller than the sum of its proper divisors (14219669256).

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

6405137856 is a wasteful number, since it uses less digits than its factorization.

6405137856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2490 (or 2455 counting only the distinct ones).

The product of its (nonzero) digits is 604800, while the sum is 45.

The square root of 6405137856 is about 80032.1051578677. The cubic root of 6405137856 is about 1857.1322300344.

The spelling of 6405137856 in words is "six billion, four hundred five million, one hundred thirty-seven thousand, eight hundred fifty-six".