21919170 has 192 divisors, whose sum is σ = 69866496. Its totient is φ = 4354560.

The previous prime is 21919169. The next prime is 21919181. The reversal of 21919170 is 7191912.

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 (13) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 592392 + ... + 592428.

It is an arithmetic number, because the mean of its divisors is an integer number (363888).

Almost surely, 2^21919170 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21919170, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34933248).

21919170 is an abundant number, since it is smaller than the sum of its proper divisors (47947326).

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

21919170 is a wasteful number, since it uses less digits than its factorization.

21919170 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105 (or 98 counting only the distinct ones).

The product of its (nonzero) digits is 1134, while the sum is 30.

The square root of 21919170 is about 4681.7913238418. The cubic root of 21919170 is about 279.8603470248.

The spelling of 21919170 in words is "twenty-one million, nine hundred nineteen thousand, one hundred seventy".