21447030 has 64 divisors (see below), whose sum is σ = 59470848. Its totient is φ = 4892160.

The previous prime is 21447011. The next prime is 21447043. The reversal of 21447030 is 3074412.

It is a junction number, because it is equal to n+sod(n) for n = 21446988 and 21447006.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3699 + ... + 7521.

It is an arithmetic number, because the mean of its divisors is an integer number (929232).

Almost surely, 2^21447030 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21447030, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29735424).

21447030 is an abundant number, since it is smaller than the sum of its proper divisors (38023818).

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

21447030 is a wasteful number, since it uses less digits than its factorization.

21447030 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3861.

The product of its (nonzero) digits is 672, while the sum is 21.

The square root of 21447030 is about 4631.0938232776. The cubic root of 21447030 is about 277.8363424370.

The spelling of 21447030 in words is "twenty-one million, four hundred forty-seven thousand, thirty".