18640829 has 4 divisors (see below), whose sum is σ = 18722460. Its totient is φ = 18559200.

The previous prime is 18640813. The next prime is 18640841. The reversal of 18640829 is 92804681.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15784729 + 2856100 = 3973^2 + 1690^2 .

It is a cyclic number.

It is not a de Polignac number, because 18640829 - 2⁴ = 18640813 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18640792 and 18640801.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18640429) 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, 40472 + ... + 40929.

It is an arithmetic number, because the mean of its divisors is an integer number (4680615).

Almost surely, 2^18640829 is an apocalyptic number.

It is an amenable number.

18640829 is a deficient number, since it is larger than the sum of its proper divisors (81631).

18640829 is an equidigital number, since it uses as much as digits as its factorization.

18640829 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81630.

The product of its (nonzero) digits is 27648, while the sum is 38.

The square root of 18640829 is about 4317.5026346257. The cubic root of 18640829 is about 265.1480316868.

The spelling of 18640829 in words is "eighteen million, six hundred forty thousand, eight hundred twenty-nine".