18226979 has 4 divisors (see below), whose sum is σ = 18414984. Its totient is φ = 18038976.

The previous prime is 18226951. The next prime is 18226987. The reversal of 18226979 is 97962281.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 97962281 = 3259 ⋅30059.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18226979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18226079) 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, 93857 + ... + 94050.

It is an arithmetic number, because the mean of its divisors is an integer number (4603746).

Almost surely, 2^18226979 is an apocalyptic number.

18226979 is a deficient number, since it is larger than the sum of its proper divisors (188005).

18226979 is an equidigital number, since it uses as much as digits as its factorization.

18226979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 188004.

The product of its digits is 108864, while the sum is 44.

The square root of 18226979 is about 4269.3066181758. The cubic root of 18226979 is about 263.1711214131.

The spelling of 18226979 in words is "eighteen million, two hundred twenty-six thousand, nine hundred seventy-nine".