51686100 has 126 divisors (see below), whose sum is σ = 168398510. Its totient is φ = 13763520.

The previous prime is 51686081. The next prime is 51686111. The reversal of 51686100 is 168615.

It can be written as a sum of positive squares in 3 ways, for example, as 104976 + 51581124 = 324^2 + 7182^2 .

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 41 ways as a sum of consecutive naturals, for example, 72546 + ... + 73254.

Almost surely, 2^51686100 is an apocalyptic number.

51686100 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 51686100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (84199255).

51686100 is an abundant number, since it is smaller than the sum of its proper divisors (116712410).

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

51686100 is a wasteful number, since it uses less digits than its factorization.

51686100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 741 (or 719 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The square root of 51686100 is about 7189.3045560749. The cubic root of 51686100 is about 372.4985511107.

The spelling of 51686100 in words is "fifty-one million, six hundred eighty-six thousand, one hundred".