20871306 has 12 divisors (see below), whose sum is σ = 45221202. Its totient is φ = 6957096.

The previous prime is 20871299. The next prime is 20871311. The reversal of 20871306 is 60317802.

It can be written as a sum of positive squares in only one way, i.e., 20331081 + 540225 = 4509^2 + 735^2 .

It is a super-2 number, since 2×20871306² = 871222828291272, 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 20871306.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 579741 + ... + 579776.

Almost surely, 2^20871306 is an apocalyptic number.

20871306 is an abundant number, since it is smaller than the sum of its proper divisors (24349896).

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

20871306 is a wasteful number, since it uses less digits than its factorization.

20871306 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1159525 (or 1159522 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 20871306 is about 4568.5124493647. The cubic root of 20871306 is about 275.3276799170.

The spelling of 20871306 in words is "twenty million, eight hundred seventy-one thousand, three hundred six".