21836680 has 16 divisors (see below), whose sum is σ = 49132620. Its totient is φ = 8734656.

The previous prime is 21836671. The next prime is 21836699. The reversal of 21836680 is 8663812.

It can be written as a sum of positive squares in 2 ways, for example, as 20304036 + 1532644 = 4506^2 + 1238^2 .

It is an unprimeable number.

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, 272919 + ... + 272998.

Almost surely, 2^21836680 is an apocalyptic number.

21836680 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21836680 is an abundant number, since it is smaller than the sum of its proper divisors (27295940).

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

21836680 is a wasteful number, since it uses less digits than its factorization.

21836680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 545928 (or 545924 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 34.

The square root of 21836680 is about 4672.9733575102. The cubic root of 21836680 is about 279.5088327912.

The spelling of 21836680 in words is "twenty-one million, eight hundred thirty-six thousand, six hundred eighty".