21630363 has 16 divisors (see below), whose sum is σ = 29465856. Its totient is φ = 14110880.

The previous prime is 21630359. The next prime is 21630383. The reversal of 21630363 is 36303612.

It is a cyclic number.

It is not a de Polignac number, because 21630363 - 2² = 21630359 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is not an unprimeable number, because it can be changed into a prime (21630353) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36556 + ... + 37142.

It is an arithmetic number, because the mean of its divisors is an integer number (1841616).

Almost surely, 2^21630363 is an apocalyptic number.

21630363 is a deficient number, since it is larger than the sum of its proper divisors (7835493).

21630363 is a wasteful number, since it uses less digits than its factorization.

21630363 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 834.

The product of its (nonzero) digits is 1944, while the sum is 24.

The square root of 21630363 is about 4650.8454070201. The cubic root of 21630363 is about 278.6257620327.

Adding to 21630363 its reverse (36303612), we get a palindrome (57933975).

The spelling of 21630363 in words is "twenty-one million, six hundred thirty thousand, three hundred sixty-three".