20687604 has 72 divisors (see below), whose sum is σ = 56766528. Its totient is φ = 5846400.

The previous prime is 20687593. The next prime is 20687617. The reversal of 20687604 is 40678602.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 88672 + ... + 88904.

It is an arithmetic number, because the mean of its divisors is an integer number (788424).

Almost surely, 2^20687604 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20687604, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28383264).

20687604 is an abundant number, since it is smaller than the sum of its proper divisors (36078924).

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

20687604 is a wasteful number, since it uses less digits than its factorization.

20687604 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 405 (or 396 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 33.

The square root of 20687604 is about 4548.3627823647. The cubic root of 20687604 is about 274.5175187309.

The spelling of 20687604 in words is "twenty million, six hundred eighty-seven thousand, six hundred four".