21670189 has 8 divisors (see below), whose sum is σ = 23322168. Its totient is φ = 20060160.

The previous prime is 21670183. The next prime is 21670199. The reversal of 21670189 is 98107612.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1716100 + 19954089 = 1310^2 + 4467^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 21670189 - 2⁹ = 21669677 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21670183) 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, 9412 + ... + 11485.

It is an arithmetic number, because the mean of its divisors is an integer number (2915271).

Almost surely, 2^21670189 is an apocalyptic number.

It is an amenable number.

21670189 is a deficient number, since it is larger than the sum of its proper divisors (1651979).

21670189 is a wasteful number, since it uses less digits than its factorization.

21670189 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20975.

The product of its (nonzero) digits is 6048, while the sum is 34.

The square root of 21670189 is about 4655.1250251739. The cubic root of 21670189 is about 278.7966598613.

The spelling of 21670189 in words is "twenty-one million, six hundred seventy thousand, one hundred eighty-nine".