18820665 has 24 divisors (see below), whose sum is σ = 33022080. Its totient is φ = 9914784.

The previous prime is 18820663. The next prime is 18820667. The reversal of 18820665 is 56602881.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (18820663) and next prime (18820667).

It is not a de Polignac number, because 18820665 - 2¹ = 18820663 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (18820661) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1216 + ... + 6254.

It is an arithmetic number, because the mean of its divisors is an integer number (1375920).

Almost surely, 2^18820665 is an apocalyptic number.

18820665 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18820665 is a deficient number, since it is larger than the sum of its proper divisors (14201415).

18820665 is a wasteful number, since it uses less digits than its factorization.

18820665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5133 (or 5130 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The square root of 18820665 is about 4338.2790366688. The cubic root of 18820665 is about 265.9979695324.

The spelling of 18820665 in words is "eighteen million, eight hundred twenty thousand, six hundred sixty-five".