18212890 has 8 divisors (see below), whose sum is σ = 32783220. Its totient is φ = 7285152.

The previous prime is 18212879. The next prime is 18212893. The reversal of 18212890 is 9821281.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 15139881 + 3073009 = 3891^2 + 1753^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (18212893) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 910635 + ... + 910654.

Almost surely, 2^18212890 is an apocalyptic number.

18212890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18212890 is a deficient number, since it is larger than the sum of its proper divisors (14570330).

18212890 is a wasteful number, since it uses less digits than its factorization.

18212890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1821296.

The product of its (nonzero) digits is 2304, while the sum is 31.

The square root of 18212890 is about 4267.6562654459. The cubic root of 18212890 is about 263.1032956973.

The spelling of 18212890 in words is "eighteen million, two hundred twelve thousand, eight hundred ninety".