20871408 has 20 divisors (see below), whose sum is σ = 53917928. Its totient is φ = 6957120.

The previous prime is 20871407. The next prime is 20871413. The reversal of 20871408 is 80417802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20871407) 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, 217363 + ... + 217458.

Almost surely, 2^20871408 is an apocalyptic number.

It is an amenable number.

20871408 is an abundant number, since it is smaller than the sum of its proper divisors (33046520).

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

20871408 is a wasteful number, since it uses less digits than its factorization.

20871408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 434832 (or 434826 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 30.

The square root of 20871408 is about 4568.5236127222. The cubic root of 20871408 is about 275.3281284335.

The spelling of 20871408 in words is "twenty million, eight hundred seventy-one thousand, four hundred eight".