21910168 has 32 divisors (see below), whose sum is σ = 48994560. Its totient is φ = 8981280.

The previous prime is 21910159. The next prime is 21910169. The reversal of 21910168 is 86101912.

It is a happy number.

It is a Smith number, since the sum of its digits (28) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21910169) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 7218 + ... + 9793.

It is an arithmetic number, because the mean of its divisors is an integer number (1531080).

Almost surely, 2^21910168 is an apocalyptic number.

21910168 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21910168 is an abundant number, since it is smaller than the sum of its proper divisors (27084392).

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

21910168 is a wasteful number, since it uses less digits than its factorization.

21910168 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17047 (or 17043 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 28.

The square root of 21910168 is about 4680.8298409577. The cubic root of 21910168 is about 279.8220297618.

The spelling of 21910168 in words is "twenty-one million, nine hundred ten thousand, one hundred sixty-eight".