51661682100 has 432 divisors, whose sum is σ = 196115920000. Its totient is φ = 11111592960.

The previous prime is 51661682099. The next prime is 51661682201. The reversal of 51661682100 is 128616615.

51661682100 is a `hidden beast` number, since 5 + 16 + 616 + 8 + 21 + 0 + 0 = 666.

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

It is a congruent number.

It is an unprimeable number.

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 143 ways as a sum of consecutive naturals, for example, 18791526 + ... + 18794274.

Almost surely, 2^51661682100 is an apocalyptic number.

51661682100 is a gapful number since it is divisible by the number (50) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51661682100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (98057960000).

51661682100 is an abundant number, since it is smaller than the sum of its proper divisors (144454237900).

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

51661682100 is a wasteful number, since it uses less digits than its factorization.

51661682100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2952 (or 2942 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The spelling of 51661682100 in words is "fifty-one billion, six hundred sixty-one million, six hundred eighty-two thousand, one hundred".