21101889 has 4 divisors (see below), whose sum is σ = 28135856. Its totient is φ = 14067924.

The previous prime is 21101887. The next prime is 21101903. The reversal of 21101889 is 98810112.

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 not a de Polignac number, because 21101889 - 2¹ = 21101887 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21101887) 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, 3516979 + ... + 3516984.

It is an arithmetic number, because the mean of its divisors is an integer number (7033964).

Almost surely, 2^21101889 is an apocalyptic number.

It is an amenable number.

21101889 is a deficient number, since it is larger than the sum of its proper divisors (7033967).

21101889 is an equidigital number, since it uses as much as digits as its factorization.

21101889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7033966.

The product of its (nonzero) digits is 1152, while the sum is 30.

The square root of 21101889 is about 4593.6792443530. The cubic root of 21101889 is about 276.3378948149.

The spelling of 21101889 in words is "twenty-one million, one hundred one thousand, eight hundred eighty-nine".