20871284 has 24 divisors (see below), whose sum is σ = 42318528. Its totient is φ = 8821440.

The previous prime is 20871283. The next prime is 20871287. The reversal of 20871284 is 48217802.

It is a super-2 number, since 2×20871284² = 871220991617312, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20871284.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20871283) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3062 + ... + 7149.

It is an arithmetic number, because the mean of its divisors is an integer number (1763272).

Almost surely, 2^20871284 is an apocalyptic number.

It is an amenable number.

20871284 is an abundant number, since it is smaller than the sum of its proper divisors (21447244).

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

20871284 is a wasteful number, since it uses less digits than its factorization.

20871284 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10295 (or 10293 counting only the distinct ones).

The product of its (nonzero) digits is 7168, while the sum is 32.

The square root of 20871284 is about 4568.5100415781. The cubic root of 20871284 is about 275.3275831779.

The spelling of 20871284 in words is "twenty million, eight hundred seventy-one thousand, two hundred eighty-four".