21100387289 has 4 divisors (see below), whose sum is σ = 22017795456. Its totient is φ = 20182979124.

The previous prime is 21100387277. The next prime is 21100387291. The reversal of 21100387289 is 98278300112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21100387289 - 2¹² = 21100383193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21100387249) 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, 458704049 + ... + 458704094.

It is an arithmetic number, because the mean of its divisors is an integer number (5504448864).

Almost surely, 2^21100387289 is an apocalyptic number.

It is an amenable number.

21100387289 is a deficient number, since it is larger than the sum of its proper divisors (917408167).

21100387289 is an equidigital number, since it uses as much as digits as its factorization.

21100387289 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 917408166.

The product of its (nonzero) digits is 48384, while the sum is 41.

The spelling of 21100387289 in words is "twenty-one billion, one hundred million, three hundred eighty-seven thousand, two hundred eighty-nine".