18620819 has 4 divisors (see below), whose sum is σ = 21280944. Its totient is φ = 15960696.

The previous prime is 18620809. The next prime is 18620821. The reversal of 18620819 is 91802681.

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

It is a cyclic number.

It is not a de Polignac number, because 18620819 - 2⁴ = 18620803 is a prime.

It is a super-2 number, since 2×18620819² = 693469800461522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18620809) 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, 1330052 + ... + 1330065.

It is an arithmetic number, because the mean of its divisors is an integer number (5320236).

Almost surely, 2^18620819 is an apocalyptic number.

18620819 is a deficient number, since it is larger than the sum of its proper divisors (2660125).

18620819 is an equidigital number, since it uses as much as digits as its factorization.

18620819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2660124.

The product of its (nonzero) digits is 6912, while the sum is 35.

The square root of 18620819 is about 4315.1847005661. The cubic root of 18620819 is about 265.0531233240.

The spelling of 18620819 in words is "eighteen million, six hundred twenty thousand, eight hundred nineteen".