20121984 has 48 divisors (see below), whose sum is σ = 57906420. Its totient is φ = 6706944.

The previous prime is 20121973. The next prime is 20121989. The reversal of 20121984 is 48912102.

It is a tau number, because it is divible by the number of its divisors (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20121989) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 7582 + ... + 9885.

Almost surely, 2^20121984 is an apocalyptic number.

20121984 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

20121984 is an abundant number, since it is smaller than the sum of its proper divisors (37784436).

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

20121984 is a wasteful number, since it uses less digits than its factorization.

20121984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17487 (or 17472 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 20121984 is about 4485.7534484187. The cubic root of 20121984 is about 271.9925026769.

The spelling of 20121984 in words is "twenty million, one hundred twenty-one thousand, nine hundred eighty-four".