16821090 has 96 divisors (see below), whose sum is σ = 51420096. Its totient is φ = 3761280.

The previous prime is 16821083. The next prime is 16821121. The reversal of 16821090 is 9012861.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 12217 + ... + 13523.

It is an arithmetic number, because the mean of its divisors is an integer number (535626).

Almost surely, 2^16821090 is an apocalyptic number.

16821090 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 16821090, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25710048).

16821090 is an abundant number, since it is smaller than the sum of its proper divisors (34599006).

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

16821090 is a wasteful number, since it uses less digits than its factorization.

16821090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1344 (or 1341 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 27.

The square root of 16821090 is about 4101.3522160380. The cubic root of 16821090 is about 256.2229604624. Note that the first 3 decimals are identical.

It can be divided in two parts, 1682 and 1090, that added together give a palindrome (2772).

The spelling of 16821090 in words is "sixteen million, eight hundred twenty-one thousand, ninety".