212121984 has 32 divisors (see below), whose sum is σ = 563450040. Its totient is φ = 70707200.

The previous prime is 212121983. The next prime is 212121989. The reversal of 212121984 is 489121212.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (32).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212121983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 275817 + ... + 276584.

Almost surely, 2^212121984 is an apocalyptic number.

212121984 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

212121984 is an abundant number, since it is smaller than the sum of its proper divisors (351328056).

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

212121984 is an equidigital number, since it uses as much as digits as its factorization.

212121984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 552418 (or 552406 counting only the distinct ones).

The product of its digits is 2304, while the sum is 30.

The square root of 212121984 is about 14564.4081239163. The cubic root of 212121984 is about 596.3875382953.

The spelling of 212121984 in words is "two hundred twelve million, one hundred twenty-one thousand, nine hundred eighty-four".