18450820 has 24 divisors (see below), whose sum is σ = 39693528. Its totient is φ = 7200000.

The previous prime is 18450811. The next prime is 18450829. The reversal of 18450820 is 2805481.

It is an interprime number because it is at equal distance from previous prime (18450811) and next prime (18450829).

It can be written as a sum of positive squares in 4 ways, for example, as 3147076 + 15303744 = 1774^2 + 3912^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18450829) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10431 + ... + 12070.

It is an arithmetic number, because the mean of its divisors is an integer number (1653897).

Almost surely, 2^18450820 is an apocalyptic number.

18450820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18450820 is an abundant number, since it is smaller than the sum of its proper divisors (21242708).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18450820 is a wasteful number, since it uses less digits than its factorization.

18450820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22551 (or 22549 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 28.

The square root of 18450820 is about 4295.4417700628. The cubic root of 18450820 is about 264.2440542355.

It can be divided in two parts, 184508 and 20, that added together give a triangular number (184528 = T₆₀₇).

The spelling of 18450820 in words is "eighteen million, four hundred fifty thousand, eight hundred twenty".