20866380 has 24 divisors (see below), whose sum is σ = 58426032. Its totient is φ = 5564352.

The previous prime is 20866357. The next prime is 20866381. The reversal of 20866380 is 8366802.

It is not an unprimeable number, because it can be changed into a prime (20866381) 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 7 ways as a sum of consecutive naturals, for example, 173827 + ... + 173946.

It is an arithmetic number, because the mean of its divisors is an integer number (2434418).

Almost surely, 2^20866380 is an apocalyptic number.

20866380 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20866380 is an abundant number, since it is smaller than the sum of its proper divisors (37559652).

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

20866380 is a wasteful number, since it uses less digits than its factorization.

20866380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 347785 (or 347783 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 33.

The square root of 20866380 is about 4567.9732923913. The cubic root of 20866380 is about 275.3060174670.

The spelling of 20866380 in words is "twenty million, eight hundred sixty-six thousand, three hundred eighty".