20907984 has 20 divisors (see below), whose sum is σ = 54012416. Its totient is φ = 6969312.

The previous prime is 20907983. The next prime is 20908001. The reversal of 20907984 is 48970902.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20907983) 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, 217744 + ... + 217839.

Almost surely, 2^20907984 is an apocalyptic number.

20907984 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

20907984 is an abundant number, since it is smaller than the sum of its proper divisors (33104432).

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

20907984 is a wasteful number, since it uses less digits than its factorization.

20907984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 435594 (or 435588 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 39.

The square root of 20907984 is about 4572.5249042515. The cubic root of 20907984 is about 275.4888670659.

The spelling of 20907984 in words is "twenty million, nine hundred seven thousand, nine hundred eighty-four".