21466920 has 96 divisors (see below), whose sum is σ = 68522400. Its totient is φ = 5379072.

The previous prime is 21466909. The next prime is 21466957. The reversal of 21466920 is 2966412.

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

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 34371 + ... + 34989.

It is an arithmetic number, because the mean of its divisors is an integer number (713775).

Almost surely, 2^21466920 is an apocalyptic number.

21466920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21466920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34261200).

21466920 is an abundant number, since it is smaller than the sum of its proper divisors (47055480).

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

21466920 is a wasteful number, since it uses less digits than its factorization.

21466920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 667 (or 646 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 30.

The square root of 21466920 is about 4633.2407664614. The cubic root of 21466920 is about 277.9222044795.

The spelling of 21466920 in words is "twenty-one million, four hundred sixty-six thousand, nine hundred twenty".