18216149 has 4 divisors (see below), whose sum is σ = 20818464. Its totient is φ = 15613836.

The previous prime is 18216139. The next prime is 18216151. The reversal of 18216149 is 94161281.

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 18216149 - 2²⁴ = 1438933 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 (18216109) 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, 1301147 + ... + 1301160.

It is an arithmetic number, because the mean of its divisors is an integer number (5204616).

Almost surely, 2^18216149 is an apocalyptic number.

It is an amenable number.

18216149 is a deficient number, since it is larger than the sum of its proper divisors (2602315).

18216149 is an equidigital number, since it uses as much as digits as its factorization.

18216149 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2602314.

The product of its digits is 3456, while the sum is 32.

The square root of 18216149 is about 4268.0380738695. The cubic root of 18216149 is about 263.1189879260.

The spelling of 18216149 in words is "eighteen million, two hundred sixteen thousand, one hundred forty-nine".