51685340 has 24 divisors (see below), whose sum is σ = 124045152. Its totient is φ = 17720640.

The previous prime is 51685327. The next prime is 51685349. The reversal of 51685340 is 4358615.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 51685297 and 51685306.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51685349) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 184451 + ... + 184730.

It is an arithmetic number, because the mean of its divisors is an integer number (5168548).

Almost surely, 2^51685340 is an apocalyptic number.

It is an amenable number.

51685340 is an abundant number, since it is smaller than the sum of its proper divisors (72359812).

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

51685340 is a wasteful number, since it uses less digits than its factorization.

51685340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 369197 (or 369195 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 32.

The square root of 51685340 is about 7189.2516995860. The cubic root of 51685340 is about 372.4967253439.

It can be divided in two parts, 51685 and 340, that added together give a palindrome (52025).

The spelling of 51685340 in words is "fifty-one million, six hundred eighty-five thousand, three hundred forty".