51353786646 has 80 divisors (see below), whose sum is σ = 116303440176. Its totient is φ = 16935381504.

The previous prime is 51353786639. The next prime is 51353786681. The reversal of 51353786646 is 64668735315.

51353786646 is a `hidden beast` number, since 5 + 1 + 3 + 537 + 8 + 66 + 46 = 666.

It is a super-2 number, since 2×51353786646² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a junction number, because it is equal to n+sod(n) for n = 51353786592 and 51353786601.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 6809790 + ... + 6817326.

Almost surely, 2^51353786646 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51353786646, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (58151720088).

51353786646 is an abundant number, since it is smaller than the sum of its proper divisors (64949653530).

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

51353786646 is a wasteful number, since it uses less digits than its factorization.

51353786646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7995 (or 7986 counting only the distinct ones).

The product of its digits is 10886400, while the sum is 54.

The spelling of 51353786646 in words is "fifty-one billion, three hundred fifty-three million, seven hundred eighty-six thousand, six hundred forty-six".