21212009998 has 8 divisors (see below), whose sum is σ = 33689662992. Its totient is φ = 9982122336.

The previous prime is 21212009993. The next prime is 21212010011. The reversal of 21212009998 is 89990021212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212009993) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 311941290 + ... + 311941357.

It is an arithmetic number, because the mean of its divisors is an integer number (4211207874).

Almost surely, 2^21212009998 is an apocalyptic number.

21212009998 is a deficient number, since it is larger than the sum of its proper divisors (12477652994).

21212009998 is a wasteful number, since it uses less digits than its factorization.

21212009998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 623882666.

The product of its (nonzero) digits is 46656, while the sum is 43.

The spelling of 21212009998 in words is "twenty-one billion, two hundred twelve million, nine thousand, nine hundred ninety-eight".