51696655920 has 1280 divisors, whose sum is σ = 236144885760. Its totient is φ = 10212065280.

The previous prime is 51696655909. The next prime is 51696655931. The reversal of 51696655920 is 2955669615.

51696655920 is a `hidden beast` number, since 5 + 1 + 6 + 9 + 66 + 559 + 20 = 666.

It is an interprime number because it is at equal distance from previous prime (51696655909) and next prime (51696655931).

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

It is an unprimeable number.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 270663025 + ... + 270663215.

It is an arithmetic number, because the mean of its divisors is an integer number (184488192).

Almost surely, 2^51696655920 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 51696655920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (118072442880).

51696655920 is an abundant number, since it is smaller than the sum of its proper divisors (184448229840).

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

51696655920 is a wasteful number, since it uses less digits than its factorization.

51696655920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 262 (or 238 counting only the distinct ones).

The product of its (nonzero) digits is 4374000, while the sum is 54.

The spelling of 51696655920 in words is "fifty-one billion, six hundred ninety-six million, six hundred fifty-five thousand, nine hundred twenty".