21185802 has 48 divisors (see below), whose sum is σ = 50854752. Its totient is φ = 6320160.

The previous prime is 21185789. The next prime is 21185821. The reversal of 21185802 is 20858112.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12468 + ... + 14064.

It is an arithmetic number, because the mean of its divisors is an integer number (1059474).

Almost surely, 2^21185802 is an apocalyptic number.

21185802 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21185802, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25427376).

21185802 is an abundant number, since it is smaller than the sum of its proper divisors (29668950).

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

21185802 is a wasteful number, since it uses less digits than its factorization.

21185802 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1683 (or 1680 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 27.

The square root of 21185802 is about 4602.8037107832. The cubic root of 21185802 is about 276.7037020791.

The spelling of 21185802 in words is "twenty-one million, one hundred eighty-five thousand, eight hundred two".