51666120000 has 560 divisors, whose sum is σ = 207102456000. Its totient is φ = 12522240000.

The previous prime is 51666119971. The next prime is 51666120059. The reversal of 51666120000 is 2166615.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 11877826 + ... + 11882174.

Almost surely, 2^51666120000 is an apocalyptic number.

51666120000 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 51666120000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (103551228000).

51666120000 is an abundant number, since it is smaller than the sum of its proper divisors (155436336000).

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

51666120000 is a wasteful number, since it uses less digits than its factorization.

51666120000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4401 (or 4370 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

Adding to 51666120000 its reverse (2166615), we get a palindrome (51668286615).

The spelling of 51666120000 in words is "fifty-one billion, six hundred sixty-six million, one hundred twenty thousand".