21068880 has 80 divisors (see below), whose sum is σ = 74649984. Its totient is φ = 4815360.

The previous prime is 21068869. The next prime is 21068893. The reversal of 21068880 is 8886012.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4591 + ... + 7950.

Almost surely, 2^21068880 is an apocalyptic number.

21068880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21068880 is an abundant number, since it is smaller than the sum of its proper divisors (53581104).

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

21068880 is a wasteful number, since it uses less digits than its factorization.

21068880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12564 (or 12558 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 33.

The square root of 21068880 is about 4590.0849665338. The cubic root of 21068880 is about 276.1937308187.

The spelling of 21068880 in words is "twenty-one million, sixty-eight thousand, eight hundred eighty".