21443630 has 64 divisors (see below), whose sum is σ = 45577728. Its totient is φ = 7188480.

The previous prime is 21443629. The next prime is 21443657. The reversal of 21443630 is 3634412.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21443596 and 21443605.

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, 68354 + ... + 68666.

It is an arithmetic number, because the mean of its divisors is an integer number (712152).

Almost surely, 2^21443630 is an apocalyptic number.

21443630 is an abundant number, since it is smaller than the sum of its proper divisors (24134098).

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

21443630 is a wasteful number, since it uses less digits than its factorization.

21443630 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 381.

The product of its (nonzero) digits is 1728, while the sum is 23.

The square root of 21443630 is about 4630.7267248241. The cubic root of 21443630 is about 277.8216598525.

The spelling of 21443630 in words is "twenty-one million, four hundred forty-three thousand, six hundred thirty".