21668108 has 24 divisors (see below), whose sum is σ = 47276544. Its totient is φ = 8442000.

The previous prime is 21668107. The next prime is 21668111. The reversal of 21668108 is 80186612.

It is not an unprimeable number, because it can be changed into a prime (21668107) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34868 + ... + 35483.

It is an arithmetic number, because the mean of its divisors is an integer number (1969856).

Almost surely, 2^21668108 is an apocalyptic number.

21668108 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21668108 is an abundant number, since it is smaller than the sum of its proper divisors (25608436).

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

21668108 is a wasteful number, since it uses less digits than its factorization.

21668108 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70373 (or 70371 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 32.

The square root of 21668108 is about 4654.9015027173. The cubic root of 21668108 is about 278.7877352441.

The spelling of 21668108 in words is "twenty-one million, six hundred sixty-eight thousand, one hundred eight".