21493189 has 8 divisors (see below), whose sum is σ = 22226048. Its totient is φ = 20768400.

The previous prime is 21493159. The next prime is 21493193. The reversal of 21493189 is 98139412.

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 21493189 - 2¹³ = 21484997 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21493139) 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, 3664 + ... + 7510.

It is an arithmetic number, because the mean of its divisors is an integer number (2778256).

Almost surely, 2^21493189 is an apocalyptic number.

It is an amenable number.

21493189 is a deficient number, since it is larger than the sum of its proper divisors (732859).

21493189 is a wasteful number, since it uses less digits than its factorization.

21493189 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4035.

The product of its digits is 15552, while the sum is 37.

The square root of 21493189 is about 4636.0747405537. The cubic root of 21493189 is about 278.0355224349.

The spelling of 21493189 in words is "twenty-one million, four hundred ninety-three thousand, one hundred eighty-nine".