51685830 has 256 divisors, whose sum is σ = 174182400. Its totient is φ = 10644480.

The previous prime is 51685819. The next prime is 51685847. The reversal of 51685830 is 3858615.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 1260610 + ... + 1260650.

It is an arithmetic number, because the mean of its divisors is an integer number (680400).

Almost surely, 2^51685830 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51685830, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (87091200).

51685830 is an abundant number, since it is smaller than the sum of its proper divisors (122496570).

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

51685830 is a wasteful number, since it uses less digits than its factorization.

51685830 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116 (or 110 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 36.

The square root of 51685830 is about 7189.2857781563. The cubic root of 51685830 is about 372.4979024851.

The spelling of 51685830 in words is "fifty-one million, six hundred eighty-five thousand, eight hundred thirty".