21392189 has 20 divisors (see below), whose sum is σ = 26733024. Its totient is φ = 16767504.

The previous prime is 21392159. The next prime is 21392197. The reversal of 21392189 is 98129312.

It is a de Polignac number, because none of the positive numbers 2^k-21392189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21392149) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 199874 + ... + 199980.

Almost surely, 2^21392189 is an apocalyptic number.

It is an amenable number.

21392189 is a deficient number, since it is larger than the sum of its proper divisors (5340835).

21392189 is an frugal number, since it uses more digits than its factorization.

21392189 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166 (or 127 counting only the distinct ones).

The product of its digits is 7776, while the sum is 35.

The square root of 21392189 is about 4625.1690779906. The cubic root of 21392189 is about 277.5993270489.

The spelling of 21392189 in words is "twenty-one million, three hundred ninety-two thousand, one hundred eighty-nine".