51680000 has 180 divisors, whose sum is σ = 143672760. Its totient is φ = 18432000.

The previous prime is 51679997. The next prime is 51680003. The reversal of 51680000 is 8615.

It is an interprime number because it is at equal distance from previous prime (51679997) and next prime (51680003).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51680003) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 2719991 + ... + 2720009.

It is an arithmetic number, because the mean of its divisors is an integer number (798182).

Almost surely, 2^51680000 is an apocalyptic number.

51680000 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 51680000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (71836380).

51680000 is an abundant number, since it is smaller than the sum of its proper divisors (91992760).

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

51680000 is an equidigital number, since it uses as much as digits as its factorization.

51680000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72 (or 43 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 51680000 is about 7188.8803022446. The cubic root of 51680000 is about 372.4838964256.

Adding to 51680000 its reverse (8615), we get a palindrome (51688615).

The spelling of 51680000 in words is "fifty-one million, six hundred eighty thousand".