20866040 has 32 divisors (see below), whose sum is σ = 50561280. Its totient is φ = 7704192.

The previous prime is 20866031. The next prime is 20866057. The reversal of 20866040 is 4066802.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19544 + ... + 20583.

It is an arithmetic number, because the mean of its divisors is an integer number (1580040).

Almost surely, 2^20866040 is an apocalyptic number.

20866040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20866040 is an abundant number, since it is smaller than the sum of its proper divisors (29695240).

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

20866040 is a wasteful number, since it uses less digits than its factorization.

20866040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40151 (or 40147 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 26.

The square root of 20866040 is about 4567.9360766105. The cubic root of 20866040 is about 275.3045221660.

The spelling of 20866040 in words is "twenty million, eight hundred sixty-six thousand, forty".