21446920 has 64 divisors (see below), whose sum is σ = 53395200. Its totient is φ = 7687680.

The previous prime is 21446917. The next prime is 21446941. The reversal of 21446920 is 2964412.

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, 34452 + ... + 35068.

It is an arithmetic number, because the mean of its divisors is an integer number (834300).

Almost surely, 2^21446920 is an apocalyptic number.

21446920 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 21446920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26697600).

21446920 is an abundant number, since it is smaller than the sum of its proper divisors (31948280).

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

21446920 is a wasteful number, since it uses less digits than its factorization.

21446920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 718 (or 714 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 21446920 is about 4631.0819470184. The cubic root of 21446920 is about 277.8358674365.

It can be divided in two parts, 21446 and 920, that added together give a triangular number (22366 = T₂₁₁).

The spelling of 21446920 in words is "twenty-one million, four hundred forty-six thousand, nine hundred twenty".