51695440 has 20 divisors (see below), whose sum is σ = 120192084. Its totient is φ = 20678144.

The previous prime is 51695431. The next prime is 51695459. The reversal of 51695440 is 4459615.

It can be written as a sum of positive squares in 2 ways, for example, as 8714304 + 42981136 = 2952^2 + 6556^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a junction number, because it is equal to n+sod(n) for n = 51695396 and 51695405.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 323017 + ... + 323176.

Almost surely, 2^51695440 is an apocalyptic number.

It is an amenable number.

51695440 is an abundant number, since it is smaller than the sum of its proper divisors (68496644).

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

51695440 is a wasteful number, since it uses less digits than its factorization.

51695440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 646206 (or 646200 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 34.

The square root of 51695440 is about 7189.9541027742. The cubic root of 51695440 is about 372.5209873616.

It can be divided in two parts, 5169 and 5440, that added together give a square (10609 = 103²).

The spelling of 51695440 in words is "fifty-one million, six hundred ninety-five thousand, four hundred forty".