21897810219 has 8 divisors (see below), whose sum is σ = 29597040592. Its totient is φ = 14398560000.

The previous prime is 21897810199. The next prime is 21897810229. The reversal of 21897810219 is 91201879812.

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

It is not a de Polignac number, because 21897810219 - 2¹⁶ = 21897744683 is a prime.

It is a super-2 number, since 2×21897810219² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21897810229) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 49994782 + ... + 49995219.

It is an arithmetic number, because the mean of its divisors is an integer number (3699630074).

Almost surely, 2^21897810219 is an apocalyptic number.

21897810219 is a deficient number, since it is larger than the sum of its proper divisors (7699230373).

21897810219 is an equidigital number, since it uses as much as digits as its factorization.

21897810219 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99990077.

The product of its (nonzero) digits is 145152, while the sum is 48.

The spelling of 21897810219 in words is "twenty-one billion, eight hundred ninety-seven million, eight hundred ten thousand, two hundred nineteen".