21189210249 has 8 divisors (see below), whose sum is σ = 28253239840. Its totient is φ = 14125660416.

The previous prime is 21189210247. The next prime is 21189210281. The reversal of 21189210249 is 94201298112.

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

It is not a de Polignac number, because 21189210249 - 2¹ = 21189210247 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21189210247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 354 + ... + 205860.

It is an arithmetic number, because the mean of its divisors is an integer number (3531654980).

Almost surely, 2^21189210249 is an apocalyptic number.

It is an amenable number.

21189210249 is a deficient number, since it is larger than the sum of its proper divisors (7064029591).

21189210249 is a wasteful number, since it uses less digits than its factorization.

21189210249 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 239879.

The product of its (nonzero) digits is 20736, while the sum is 39.

The spelling of 21189210249 in words is "twenty-one billion, one hundred eighty-nine million, two hundred ten thousand, two hundred forty-nine".