21212439384 has 32 divisors (see below), whose sum is σ = 56150575920. Its totient is φ = 6654882816.

The previous prime is 21212439377. The next prime is 21212439497. The reversal of 21212439384 is 48393421212.

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, 25995229 + ... + 25996044.

Almost surely, 2^21212439384 is an apocalyptic number.

21212439384 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21212439384 is an abundant number, since it is smaller than the sum of its proper divisors (34938136536).

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

21212439384 is a wasteful number, since it uses less digits than its factorization.

21212439384 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51991299 (or 51991295 counting only the distinct ones).

The product of its digits is 82944, while the sum is 39.

The spelling of 21212439384 in words is "twenty-one billion, two hundred twelve million, four hundred thirty-nine thousand, three hundred eighty-four".