21663030 has 32 divisors (see below), whose sum is σ = 52876800. Its totient is φ = 5678432.

The previous prime is 21662989. The next prime is 21663041. The reversal of 21663030 is 3036612.

It is a junction number, because it is equal to n+sod(n) for n = 21662988 and 21663006.

It is a congruent number.

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, 4350 + ... + 7889.

It is an arithmetic number, because the mean of its divisors is an integer number (1652400).

Almost surely, 2^21663030 is an apocalyptic number.

21663030 is an abundant number, since it is smaller than the sum of its proper divisors (31213770).

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

21663030 is a wasteful number, since it uses less digits than its factorization.

21663030 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12308.

The product of its (nonzero) digits is 648, while the sum is 21.

The square root of 21663030 is about 4654.3560241993. The cubic root of 21663030 is about 278.7659552357.

Adding to 21663030 its reverse (3036612), we get a palindrome (24699642).

The spelling of 21663030 in words is "twenty-one million, six hundred sixty-three thousand, thirty".