18640229 has 4 divisors (see below), whose sum is σ = 18655980. Its totient is φ = 18624480.

The previous prime is 18640103. The next prime is 18640241. The reversal of 18640229 is 92204681.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 92204681 = 3391 ⋅27191.

It can be written as a sum of positive squares in 2 ways, for example, as 7236100 + 11404129 = 2690^2 + 3377^2 .

It is a cyclic number.

It is not a de Polignac number, because 18640229 - 2¹² = 18636133 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18640195 and 18640204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18640289) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5942 + ... + 8519.

It is an arithmetic number, because the mean of its divisors is an integer number (4663995).

Almost surely, 2^18640229 is an apocalyptic number.

It is an amenable number.

18640229 is a deficient number, since it is larger than the sum of its proper divisors (15751).

18640229 is a wasteful number, since it uses less digits than its factorization.

18640229 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15750.

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 18640229 is about 4317.4331494535. The cubic root of 18640229 is about 265.1451868468.

The spelling of 18640229 in words is "eighteen million, six hundred forty thousand, two hundred twenty-nine".