20687872 has 44 divisors (see below), whose sum is σ = 42004440. Its totient is φ = 10182656.

The previous prime is 20687867. The next prime is 20687893. The reversal of 20687872 is 27878602.

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, 91023 + ... + 91249.

Almost surely, 2^20687872 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 20687872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21002220).

20687872 is an abundant number, since it is smaller than the sum of its proper divisors (21316568).

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

20687872 is an equidigital number, since it uses as much as digits as its factorization.

20687872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 336 (or 318 counting only the distinct ones).

The product of its (nonzero) digits is 75264, while the sum is 40.

The square root of 20687872 is about 4548.3922434196. The cubic root of 20687872 is about 274.5187041489.

The spelling of 20687872 in words is "twenty million, six hundred eighty-seven thousand, eight hundred seventy-two".