51781684 has 12 divisors (see below), whose sum is σ = 90689508. Its totient is φ = 25870400.

The previous prime is 51781673. The next prime is 51781703. The reversal of 51781684 is 48618715.

It can be written as a sum of positive squares in 2 ways, for example, as 15444900 + 36336784 = 3930^2 + 6028^2 .

It is a super-3 number, since 3×51781684³ (a number of 24 digits) contains 333 as substring.

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, 1554 + ... + 10294.

It is an arithmetic number, because the mean of its divisors is an integer number (7557459).

Almost surely, 2^51781684 is an apocalyptic number.

It is an amenable number.

51781684 is a deficient number, since it is larger than the sum of its proper divisors (38907824).

51781684 is a wasteful number, since it uses less digits than its factorization.

51781684 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10226 (or 10224 counting only the distinct ones).

The product of its digits is 53760, while the sum is 40.

The square root of 51781684 is about 7195.9491382305. The cubic root of 51781684 is about 372.7280323818.

The spelling of 51781684 in words is "fifty-one million, seven hundred eighty-one thousand, six hundred eighty-four".