20685684 has 12 divisors (see below), whose sum is σ = 48266624. Its totient is φ = 6895224.

The previous prime is 20685683. The next prime is 20685697. The reversal of 20685684 is 48658602.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20685683) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 861892 + ... + 861915.

Almost surely, 2^20685684 is an apocalyptic number.

It is an amenable number.

20685684 is an abundant number, since it is smaller than the sum of its proper divisors (27580940).

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

20685684 is a wasteful number, since it uses less digits than its factorization.

20685684 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1723814 (or 1723812 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 39.

The square root of 20685684 is about 4548.1517125092. The cubic root of 20685684 is about 274.5090258843.

It can be divided in two parts, 20685 and 684, that multiplied together give a triangular number (14148540 = T₅₃₁₉).

The spelling of 20685684 in words is "twenty million, six hundred eighty-five thousand, six hundred eighty-four".