18891229 has 8 divisors (see below), whose sum is σ = 21833280. Its totient is φ = 16010016.

The previous prime is 18891193. The next prime is 18891251. The reversal of 18891229 is 92219881.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18891229 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18891191 and 18891200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18891289) by changing a digit.

It is an upside-down number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14539 + ... + 15784.

It is an arithmetic number, because the mean of its divisors is an integer number (2729160).

Almost surely, 2^18891229 is an apocalyptic number.

It is an amenable number.

18891229 is a deficient number, since it is larger than the sum of its proper divisors (2942051).

18891229 is an equidigital number, since it uses as much as digits as its factorization.

18891229 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30419.

The product of its digits is 20736, while the sum is 40.

The square root of 18891229 is about 4346.4041459579. The cubic root of 18891229 is about 266.3299888243.

The spelling of 18891229 in words is "eighteen million, eight hundred ninety-one thousand, two hundred twenty-nine".