21533630 has 16 divisors (see below), whose sum is σ = 39808800. Its totient is φ = 8380512.

The previous prime is 21533597. The next prime is 21533647. The reversal of 21533630 is 3633512.

It is a junction number, because it is equal to n+sod(n) for n = 21533596 and 21533605.

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 28730 + ... + 29469.

It is an arithmetic number, because the mean of its divisors is an integer number (2488050).

Almost surely, 2^21533630 is an apocalyptic number.

21533630 is a deficient number, since it is larger than the sum of its proper divisors (18275170).

21533630 is a wasteful number, since it uses less digits than its factorization.

21533630 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58243.

The product of its (nonzero) digits is 1620, while the sum is 23.

The square root of 21533630 is about 4640.4342469213. The cubic root of 21533630 is about 278.2097945383.

The spelling of 21533630 in words is "twenty-one million, five hundred thirty-three thousand, six hundred thirty".