18162820 has 24 divisors (see below), whose sum is σ = 41076504. Its totient is φ = 6706176.

The previous prime is 18162797. The next prime is 18162839. The reversal of 18162820 is 2826181.

It can be written as a sum of positive squares in 4 ways, for example, as 49284 + 18113536 = 222^2 + 4256^2 .

It is a super-3 number, since 3×18162820³ (a number of 23 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34669 + ... + 35188.

It is an arithmetic number, because the mean of its divisors is an integer number (1711521).

Almost surely, 2^18162820 is an apocalyptic number.

18162820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18162820 is an abundant number, since it is smaller than the sum of its proper divisors (22913684).

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

18162820 is a wasteful number, since it uses less digits than its factorization.

18162820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69879 (or 69877 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 28.

The square root of 18162820 is about 4261.7860105829. The cubic root of 18162820 is about 262.8619707795.

It can be divided in two parts, 181 and 62820, that added together give a square (63001 = 251²).

The spelling of 18162820 in words is "eighteen million, one hundred sixty-two thousand, eight hundred twenty".