20966840 has 16 divisors (see below), whose sum is σ = 47175480. Its totient is φ = 8386720.

The previous prime is 20966821. The next prime is 20966849. The reversal of 20966840 is 4866902.

It is a self number, because there is not a number n which added to its sum of digits gives 20966840.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20966849) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 262046 + ... + 262125.

Almost surely, 2^20966840 is an apocalyptic number.

20966840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20966840 is an abundant number, since it is smaller than the sum of its proper divisors (26208640).

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

20966840 is a wasteful number, since it uses less digits than its factorization.

20966840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 524182 (or 524178 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 35.

The square root of 20966840 is about 4578.9562129376. The cubic root of 20966840 is about 275.7471253817.

The spelling of 20966840 in words is "twenty million, nine hundred sixty-six thousand, eight hundred forty".