51699971736 has 720 divisors, whose sum is σ = 190427549400. Its totient is φ = 12985297920.

The previous prime is 51699971699. The next prime is 51699971789. The reversal of 51699971736 is 63717999615.

It is a Harshad number since it is a multiple of its sum of digits (63).

Its product of digits (19289340) is a multiple of the sum of its prime factors (210).

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 179 ways as a sum of consecutive naturals, for example, 728168581 + ... + 728168651.

Almost surely, 2^51699971736 is an apocalyptic number.

51699971736 is a gapful number since it is divisible by the number (56) 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 51699971736, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (95213774700).

51699971736 is an abundant number, since it is smaller than the sum of its proper divisors (138727577664).

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

51699971736 is a wasteful number, since it uses less digits than its factorization.

51699971736 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210 (or 119 counting only the distinct ones).

The product of its digits is 19289340, while the sum is 63.

The spelling of 51699971736 in words is "fifty-one billion, six hundred ninety-nine million, nine hundred seventy-one thousand, seven hundred thirty-six".