20866512 has 20 divisors (see below), whose sum is σ = 53905280. Its totient is φ = 6955488.

The previous prime is 20866511. The next prime is 20866513. The reversal of 20866512 is 21566802.

It is an interprime number because it is at equal distance from previous prime (20866511) and next prime (20866513).

It is a super-2 number, since 2×20866512² = 870822646092288, 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 20866512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20866511) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 217312 + ... + 217407.

It is an arithmetic number, because the mean of its divisors is an integer number (2695264).

Almost surely, 2^20866512 is an apocalyptic number.

It is an amenable number.

20866512 is an abundant number, since it is smaller than the sum of its proper divisors (33038768).

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

20866512 is a wasteful number, since it uses less digits than its factorization.

20866512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 434730 (or 434724 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 20866512 is about 4567.9877407892. The cubic root of 20866512 is about 275.3065979912.

The spelling of 20866512 in words is "twenty million, eight hundred sixty-six thousand, five hundred twelve".