51997026816 has 320 divisors, whose sum is σ = 177329602560. Its totient is φ = 14735831040.

The previous prime is 51997026773. The next prime is 51997026817. The reversal of 51997026816 is 61862079915.

51997026816 is a `hidden beast` number, since 519 + 97 + 0 + 26 + 8 + 16 = 666.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

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

It is not an unprimeable number, because it can be changed into a prime (51997026817) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12287421 + ... + 12291651.

It is an arithmetic number, because the mean of its divisors is an integer number (554155008).

Almost surely, 2^51997026816 is an apocalyptic number.

51997026816 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 51997026816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (88664801280).

51997026816 is an abundant number, since it is smaller than the sum of its proper divisors (125332575744).

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

51997026816 is a wasteful number, since it uses less digits than its factorization.

51997026816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4392 (or 4370 counting only the distinct ones).

The product of its (nonzero) digits is 1632960, while the sum is 54.

The spelling of 51997026816 in words is "fifty-one billion, nine hundred ninety-seven million, twenty-six thousand, eight hundred sixteen".