21068580 has 48 divisors (see below), whose sum is σ = 63532224. Its totient is φ = 5185920.

The previous prime is 21068569. The next prime is 21068609. The reversal of 21068580 is 8586012.

It is a Harshad number since it is a multiple of its sum of digits (30).

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 15 ways as a sum of consecutive naturals, for example, 12726 + ... + 14285.

It is an arithmetic number, because the mean of its divisors is an integer number (1323588).

Almost surely, 2^21068580 is an apocalyptic number.

21068580 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21068580 is an abundant number, since it is smaller than the sum of its proper divisors (42463644).

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

21068580 is a wasteful number, since it uses less digits than its factorization.

21068580 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27036 (or 27034 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 30.

The square root of 21068580 is about 4590.0522872839. The cubic root of 21068580 is about 276.1924199040.

The spelling of 21068580 in words is "twenty-one million, sixty-eight thousand, five hundred eighty".